diff --git a/DESCRIPTION b/DESCRIPTION
index e849ada..d6e8710 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -23,4 +23,4 @@ LinkingTo: Rcpp
 ByteCompile: yes
 Suggests: testthat
 Encoding: UTF-8
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.2
diff --git a/R/read.R b/R/read.R
index b936d70..277490e 100644
--- a/R/read.R
+++ b/R/read.R
@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2014-2021 Jan Marvin Garbuszus and Sebastian Jeworutzki
+# Copyright (C) 2014-2024 Jan Marvin Garbuszus and Sebastian Jeworutzki
 # Copyright (C) of 'convert.dates' and 'missing.types' Thomas Lumley
 #
 # This program is free software; you can redistribute it and/or modify it
@@ -29,7 +29,7 @@
 #'  "label_(integer code)".
 #' @param encoding \emph{character.} Strings can be converted from Windows-1252
 #'  or UTF-8 to system encoding. Options are "latin1" or "UTF-8" to specify
-#'  target encoding explicitly. Stata 14, 15 and 16 files are UTF-8 encoded and
+#'  target encoding explicitly. Since Stata 14 files are UTF-8 encoded and
 #'  may contain strings which can't be displayed in the current locale.
 #'  Set encoding=NULL to stop reencoding.
 #' @param fromEncoding \emph{character.} We expect strings to be encoded as
@@ -93,6 +93,13 @@
 #'
 #' Reading dta-files of older and newer versions than 13 was introduced
 #'  with version 0.8.
+#'
+#' Stata 18 introduced alias variables and frame files. Alias variables are
+#'  currently ignored when reading the file and a warning is printed. Stata
+#'  frame files (file extension `.dtas`) contain zipped `dta` files which can
+#'  be loaded individually. The read test provides an example how to construct
+#'  the alias variables from a Stata frame file.
+#'
 #' @return The function returns a data.frame with attributes. The attributes
 #'  include
 #' \describe{
@@ -127,7 +134,7 @@
 #' \dontrun{
 #'   library(readstata13)
 #'   r13 <- read.dta13("https://www.stata-press.com/data/r13/auto.dta")
-#' } 
+#' }
 #' @author Jan Marvin Garbuszus \email{jan.garbuszus@@ruhr-uni-bochum.de}
 #' @author Sebastian Jeworutzki \email{sebastian.jeworutzki@@ruhr-uni-bochum.de}
 #' @useDynLib readstata13, .registration = TRUE
@@ -212,6 +219,7 @@ read.dta13 <- function(file, convert.factors = TRUE, generate.factors=FALSE,
 
   sstr     <- 2045
   sstrl    <- 32768
+  salias   <- 65525
   sdouble  <- 65526
   sfloat   <- 65527
   slong    <- 65528
diff --git a/R/readstata13.R b/R/readstata13.R
index da6dd7d..e7caea4 100644
--- a/R/readstata13.R
+++ b/R/readstata13.R
@@ -8,10 +8,9 @@
 #'
 #' @name readstata13
 #' @aliases readstata13-package
-#' @docType package
 #' @useDynLib readstata13, .registration = TRUE
 #' @import Rcpp
 #' @note If you catch a bug, please do not sue us, we do not have any money.
 #' @seealso \code{\link[foreign]{read.dta}} and \code{memisc} for dta files from
 #'  Stata Versions < 13
-NULL
+"_PACKAGE"
diff --git a/R/save.R b/R/save.R
index 11462a4..e90e390 100644
--- a/R/save.R
+++ b/R/save.R
@@ -33,8 +33,8 @@
 #'  to Stata date time format. Code from \code{foreign::write.dta}
 #' @param convert.underscore \emph{logical.} If \code{TRUE}, all non numerics or
 #' non alphabet characters will be converted to underscores.
-#' @param tz \emph{character.} time zone specification to be used for 
-#'  POSIXct values and dates (if convert.dates is TRUE). ‘""’ is the current 
+#' @param tz \emph{character.} time zone specification to be used for
+#'  POSIXct values and dates (if convert.dates is TRUE). ‘""’ is the current
 #'  time zone, and ‘"GMT"’ is UTC  (Universal Time, Coordinated).
 #' @param add.rownames \emph{logical.} If \code{TRUE}, a new variable rownames
 #'  will be added to the dta-file.
@@ -42,7 +42,7 @@
 #'  use all of Statas numeric-vartypes.
 #' @param version \emph{numeric.} Stata format for the resulting dta-file either
 #'  Stata version number (6 - 16) or the internal Stata dta-format (e.g. 117 for
-#'  Stata 13). Experimental support for large datasets: Use version="15mp" to 
+#'  Stata 13). Support for large datasets: Use version="15mp" to
 #'  save the dataset in the new Stata 15/16 MP file format. This feature is not
 #'  thoroughly tested yet.
 #' @return The function writes a dta-file to disk. The following features of the
@@ -68,7 +68,7 @@
 #' \dontrun{
 #'   library(readstata13)
 #'   save.dta13(cars, file="cars.dta")
-#' } 
+#' }
 #' @author Jan Marvin Garbuszus \email{jan.garbuszus@@ruhr-uni-bochum.de}
 #' @author Sebastian Jeworutzki \email{sebastian.jeworutzki@@ruhr-uni-bochum.de}
 #' @useDynLib readstata13, .registration = TRUE
@@ -104,10 +104,7 @@ save.dta13 <- function(data, file, data.label=NULL, time.stamp=TRUE,
   if (version==6)
     version <- 108
 
-  if (version == 119)
-    message("Support for Stata 15/16 MP (119) format is experimental and not thoroughly tested.")
-
-  if (version<102 | version == 109 | version == 116 | version>119)
+  if (version<102 | version == 109 | version == 116 | version>121)
     stop("Version mismatch abort execution. No Data was saved.")
 
   sstr     <- 2045
diff --git a/inst/extdata/myproject2.dtas b/inst/extdata/myproject2.dtas
new file mode 100644
index 0000000..8feb1f5
Binary files /dev/null and b/inst/extdata/myproject2.dtas differ
diff --git a/inst/include/readstata.h b/inst/include/readstata.h
index 720475f..f9f7785 100644
--- a/inst/include/readstata.h
+++ b/inst/include/readstata.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2017 Jan Marvin Garbuszus and Sebastian Jeworutzki
+ * Copyright (C) 2015-2024 Jan Marvin Garbuszus and Sebastian Jeworutzki
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -155,6 +155,8 @@ inline Rcpp::IntegerVector calc_rowlength(Rcpp::IntegerVector vartype) {
     case STATA_STRL:
       rlen(i) = 8;
       break;
+    case STATA_ALIAS: // 0
+      break;
     default:
       rlen(i) = type;
     break;
diff --git a/inst/include/statadefines.h b/inst/include/statadefines.h
index 2bda863..c7ad09a 100644
--- a/inst/include/statadefines.h
+++ b/inst/include/statadefines.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 Jan Marvin Garbuszus and Sebastian Jeworutzki
+ * Copyright (C) 2015-2023 Jan Marvin Garbuszus and Sebastian Jeworutzki
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -53,6 +53,7 @@
 #define STATA_INT 65528
 #define STATA_FLOAT 65527
 #define STATA_DOUBLE 65526
+#define STATA_ALIAS 65525
 
 #define STATA_STR 2045
 #define STATA_SHORT_STR 244
diff --git a/man/read.dta13.Rd b/man/read.dta13.Rd
index e4072a9..5bc4f45 100644
--- a/man/read.dta13.Rd
+++ b/man/read.dta13.Rd
@@ -36,7 +36,7 @@ are found, unique labels will be generated according the following scheme:
 
 \item{encoding}{\emph{character.} Strings can be converted from Windows-1252
 or UTF-8 to system encoding. Options are "latin1" or "UTF-8" to specify
-target encoding explicitly. Stata 14, 15 and 16 files are UTF-8 encoded and
+target encoding explicitly. Since Stata 14 files are UTF-8 encoded and
 may contain strings which can't be displayed in the current locale.
 Set encoding=NULL to stop reencoding.}
 
@@ -141,6 +141,12 @@ In R, you may use rownames to store characters (see for instance
 
 Reading dta-files of older and newer versions than 13 was introduced
  with version 0.8.
+
+Stata 18 introduced alias variables and frame files. Alias variables are
+ currently ignored when reading the file and a warning is printed. Stata
+ frame files (file extension `.dtas`) contain zipped `dta` files which can
+ be loaded individually. The read test provides an example how to construct
+ the alias variables from a Stata frame file.
 }
 \note{
 read.dta13 uses GPL 2 licensed code by Thomas Lumley and R-core members
@@ -150,7 +156,7 @@ read.dta13 uses GPL 2 licensed code by Thomas Lumley and R-core members
 \dontrun{
   library(readstata13)
   r13 <- read.dta13("https://www.stata-press.com/data/r13/auto.dta")
-} 
+}
 }
 \references{
 Stata Corp (2014): Description of .dta file format
diff --git a/man/save.dta13.Rd b/man/save.dta13.Rd
index cbf9fbf..1db6433 100644
--- a/man/save.dta13.Rd
+++ b/man/save.dta13.Rd
@@ -37,8 +37,8 @@ hexcode.}
 \item{convert.dates}{\emph{logical.} If \code{TRUE}, dates will be converted
 to Stata date time format. Code from \code{foreign::write.dta}}
 
-\item{tz}{\emph{character.} time zone specification to be used for 
-POSIXct values and dates (if convert.dates is TRUE). ‘""’ is the current 
+\item{tz}{\emph{character.} time zone specification to be used for
+POSIXct values and dates (if convert.dates is TRUE). ‘""’ is the current
 time zone, and ‘"GMT"’ is UTC  (Universal Time, Coordinated).}
 
 \item{add.rownames}{\emph{logical.} If \code{TRUE}, a new variable rownames
@@ -49,7 +49,7 @@ use all of Statas numeric-vartypes.}
 
 \item{version}{\emph{numeric.} Stata format for the resulting dta-file either
 Stata version number (6 - 16) or the internal Stata dta-format (e.g. 117 for
-Stata 13). Experimental support for large datasets: Use version="15mp" to 
+Stata 13). Support for large datasets: Use version="15mp" to
 save the dataset in the new Stata 15/16 MP file format. This feature is not
 thoroughly tested yet.}
 
@@ -80,7 +80,7 @@ into a dta-file.
 \dontrun{
   library(readstata13)
   save.dta13(cars, file="cars.dta")
-} 
+}
 }
 \references{
 Stata Corp (2014): Description of .dta file format
diff --git a/src/read_data.cpp b/src/read_data.cpp
index c6028ec..437bb77 100644
--- a/src/read_data.cpp
+++ b/src/read_data.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2018 Jan Marvin Garbuszus and Sebastian Jeworutzki
+ * Copyright (C) 2014-2024 Jan Marvin Garbuszus and Sebastian Jeworutzki
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -46,6 +46,12 @@ List read_data(FILE * file,
       SET_VECTOR_ELT(df, i, IntegerVector(no_init(nn)));
       break;
 
+    // return correct column size and create a warning
+    case STATA_ALIAS:
+      SET_VECTOR_ELT(df, i, CharacterVector(no_init(nn)));
+      Rf_warning("File contains unhandled alias variable in column: %d", i + 1);
+      break;
+
     default:
       SET_VECTOR_ELT(df, i, CharacterVector(no_init(nn)));
     break;
@@ -166,6 +172,7 @@ List read_data(FILE * file,
         break;
       }
       case 118:
+      case 120:
       {
         int16_t v = 0;
         int64_t o = 0, z = 0;
@@ -193,6 +200,7 @@ List read_data(FILE * file,
         break;
       }
       case 119:
+      case 121:
       {
         int32_t v = 0;
         int64_t o = 0, z = 0;
@@ -221,8 +229,13 @@ List read_data(FILE * file,
       }
       }
         break;
+      }
+      case STATA_ALIAS:
+      {
+        break; // do nothing
       }
         // case < 0:
+        // case STATA_ALIAS
       default:
       {
         // skip to the next valid case
diff --git a/src/read_dta.cpp b/src/read_dta.cpp
index 94d8a9e..1703cca 100644
--- a/src/read_dta.cpp
+++ b/src/read_dta.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014-2023 Jan Marvin Garbuszus and Sebastian Jeworutzki
+ * Copyright (C) 2014-2024 Jan Marvin Garbuszus and Sebastian Jeworutzki
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -38,7 +38,7 @@ List read_dta(FILE * file,
   */
 
   int8_t fversion = 117L; //f = first
-  int8_t lversion = 119L; //l = last
+  int8_t lversion = 121L; //l = last
 
   std::string version(3, '\0');
   readstring(version, file, version.size());
@@ -74,6 +74,8 @@ List read_dta(FILE * file,
     break;
   case 118:
   case 119:
+  case 120:
+  case 121:
     nvarnameslen = 129;
     nformatslen = 57;
     nvalLabelslen = 129;
@@ -106,9 +108,9 @@ List read_dta(FILE * file,
   */
 
   uint32_t k = 0;
-  if (release < 119)
+  if (release < 119 || release == 120)
     k = readbin((uint16_t)k, file, swapit);
-  if (release == 119)
+  if (release == 119 || release == 121)
     k = readbin(k, file, swapit);
 
   //</K>
@@ -123,7 +125,7 @@ List read_dta(FILE * file,
 
   if (release == 117)
     n = readbin((uint32_t)n, file, swapit);
-  if ((release == 118) | (release == 119))
+  if ((release >= 118) && (release <= 121))
     n = readbin(n, file, swapit);
 
   //</N>
@@ -146,7 +148,7 @@ List read_dta(FILE * file,
 
   if (release == 117)
     ndlabel = readbin((int8_t)ndlabel, file, swapit);
-  if ((release == 118) | (release == 119))
+  if ((release >= 118) && (release <= 121))
     ndlabel = readbin(ndlabel, file, swapit);
 
   std::string datalabel(ndlabel, '\0');
@@ -224,6 +226,7 @@ List read_dta(FILE * file,
   * vartypes.
   * 0-2045: strf (String: Max length 2045)
   * 32768:  strL (long String: Max length 2 billion)
+  * 65525:  alias
   * 65526:  double
   * 65527:  float
   * 65528:  long
@@ -274,9 +277,9 @@ List read_dta(FILE * file,
   {
     uint32_t nsortlist = 0;
 
-    if ((release == 117) | (release == 118))
+    if ((release == 117) || (release == 118) || (release == 120))
       nsortlist = readbin((uint16_t)nsortlist, file, swapit);
-    if (release == 119)
+    if (release == 119 || release == 121)
       nsortlist = readbin(nsortlist, file, swapit);
 
     sortlist[i] = nsortlist;
@@ -530,6 +533,8 @@ List read_dta(FILE * file,
     }
     case 118:
     case 119:
+    case 120:
+    case 121:
     {
       uint32_t v = 0;
       uint64_t o = 0;
diff --git a/src/save_dta.cpp b/src/save_dta.cpp
index 5805c7e..7a944e9 100644
--- a/src/save_dta.cpp
+++ b/src/save_dta.cpp
@@ -76,6 +76,8 @@ int stata_save(const char * filePath, Rcpp::DataFrame dat)
     break;
   case 118:
   case 119:
+  case 120:
+  case 121:
     nvarnameslen = 129;
     nformatslen = 57;
     nvalLabelslen = 129;
@@ -152,14 +154,14 @@ int stata_save(const char * filePath, Rcpp::DataFrame dat)
     writestr(byteord, byteord.size(), dta);
     writestr(sbyteorder, 3, dta); // LSF
     writestr(K, K.size(), dta);
-    if (release < 119)
+    if (release < 119 || release == 120)
       writebin((int16_t)k, dta, swapit);
-    if (release == 119)
+    if (release == 119 || release == 121)
       writebin(k, dta, swapit);
     writestr(num, num.size(), dta);
     if (release == 117)
       writebin((int32_t)n, dta, swapit);
-    if ((release == 118) | (release == 119))
+    if ((release == 118) | (release == 119) | (release == 120) | (release == 121))
       writebin(n, dta, swapit);
     writestr(lab, lab.size(), dta);
 
@@ -178,7 +180,7 @@ int stata_save(const char * filePath, Rcpp::DataFrame dat)
 
       if (release == 117)
         writebin((uint8_t)ndlabel, dta, swapit);
-      if ((release == 118) | (release == 119))
+      if ((release == 118) | (release == 119) | (release == 120) | (release == 121))
         writebin(ndlabel, dta, swapit);
 
       writestr(datalabel,datalabel.size(), dta);
@@ -189,7 +191,7 @@ int stata_save(const char * filePath, Rcpp::DataFrame dat)
       if (release == 117) {
         writebin(zero, dta, swapit);
       }
-      if ((release == 118) | (release == 119)) {
+      if ((release == 118) | (release == 119) | (release == 120) | (release == 121)) {
         writebin(zero, dta, swapit);
         writebin(zero, dta, swapit);
       }
@@ -257,10 +259,10 @@ int stata_save(const char * filePath, Rcpp::DataFrame dat)
     {
       uint32_t nsortlist = 0;
 
-      if ((release == 117) | (release == 118)) {
+      if ((release == 117) | (release == 118) | (release == 120)) {
         writebin((uint16_t)nsortlist, dta, swapit);
       }
-      if (release == 119) {
+      if ((release == 119) | (release == 121)) {
         writebin(nsortlist, dta, swapit);
       }
     }
@@ -496,6 +498,7 @@ int stata_save(const char * filePath, Rcpp::DataFrame dat)
             break;
           }
             case 118:
+            case 120:
           {
             int16_t v = i+1;
             int64_t o = j+1;
@@ -519,6 +522,7 @@ int stata_save(const char * filePath, Rcpp::DataFrame dat)
             break;
           }
             case 119:
+            case 121:
           {
             int32_t v = i+1;
             int64_t o = j+1;
@@ -575,7 +579,7 @@ int stata_save(const char * filePath, Rcpp::DataFrame dat)
       writebin(v, dta, swapit);
       if (release == 117)
         writebin((uint32_t)o, dta, swapit);
-      if ((release == 118) | (release == 119))
+      if ((release == 118) | (release == 119) | (release == 120) | (release == 121))
         writebin(o, dta, swapit);
       writebin(t, dta, swapit);
       writebin(len, dta, swapit);
diff --git a/tests/testthat/test_read.R b/tests/testthat/test_read.R
index 52cadbc..4f66c9f 100644
--- a/tests/testthat/test_read.R
+++ b/tests/testthat/test_read.R
@@ -248,3 +248,64 @@ test_that("various datetime conversions", {
   dddates <- read.dta13(datetime, convert.dates = TRUE)
   expect_true(all.equal(dd, dddates, check.attributes = FALSE))
 })
+
+test_that("reading file format 120 works", {
+
+  fl <- system.file("extdata", "myproject2.dtas", package="readstata13")
+
+  tmp <- tempdir()
+
+  fls <- unzip(fl, exdir = tmp)
+
+  # data name, dta file name, dta version
+  data_fram <- strsplit(readLines(fls[1])[-c(1:2)], " ")
+  data_fram <- as.data.frame(do.call("rbind", data_fram))
+
+  expect_equal(data_fram$V1, c("persons", "counties"))
+
+  # read dtas
+  dtas <- fls[tools::file_ext(fls) == "dta"]
+  expect_equal(basename(dtas), paste0(data_fram$V2, ".dta"))
+
+  expect_warning(
+    df1 <- read.dta13(dtas[1]),
+    "File contains unhandled alias variable in column: 5"
+  )
+  df2 <- read.dta13(dtas[2], convert.factors = FALSE)
+
+  expect_equal(attr(df1, "version"), as.integer(data_fram$V3[1]))
+  expect_equal(attr(df2, "version"), as.integer(data_fram$V3[2]))
+
+  # backup order
+  nams <- names(df1)
+
+  # merge: fralias_from in attr(df1, "expansion.fields") tells what to merge
+  df <- merge(
+    df1[-which(names(df1) == "median")],
+    df2,
+    by = "countyid",
+    all.x = TRUE
+  )
+
+  # update names
+  as_name <- attr(df1, "expansion.fields")[[16]]
+  nams2 <- names(df)
+  nams2[nams2 == as_name[3]] <- as_name[1]
+  names(df) <- nams2
+
+  # resore expected order
+  df <- df[nams]
+
+  # restore order
+  df <- df[order(df$personid), ]
+
+  expect_equal(
+    df$personid, 1:20
+  )
+
+  expect_equal(
+    c("personid", "countyid", "income", "counties", "median", "ratio"),
+    names(df)
+  )
+
+})
diff --git a/tests/testthat/test_save.R b/tests/testthat/test_save.R
index b303b49..b5873a0 100644
--- a/tests/testthat/test_save.R
+++ b/tests/testthat/test_save.R
@@ -109,6 +109,8 @@ dir.create("data")
 
 dd <- mtcars
 
+save.dta13(dd, "data/dta_121.dta", version = 121, compress = TRUE)
+save.dta13(dd, "data/dta_120.dta", version = 120, compress = TRUE)
 save.dta13(dd, "data/dta_119.dta", version = 119, compress = TRUE)
 save.dta13(dd, "data/dta_118.dta", version = 118, compress = TRUE)
 save.dta13(dd, "data/dta_117.dta", version = 117, compress = TRUE)
@@ -126,6 +128,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104, compress = TRUE)
 save.dta13(dd, "data/dta_103.dta", version = 103, compress = TRUE)
 save.dta13(dd, "data/dta_102.dta", version = 102, compress = TRUE)
 
+dd121 <- read.dta13("data/dta_121.dta")
+dd120 <- read.dta13("data/dta_120.dta")
 dd119 <- read.dta13("data/dta_119.dta")
 dd118 <- read.dta13("data/dta_118.dta")
 dd117 <- read.dta13("data/dta_117.dta")
@@ -147,6 +151,8 @@ dd102 <- read.dta13("data/dta_102.dta")
 unlink("data", recursive = TRUE)
 
 test_that("compress", {
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -176,6 +182,8 @@ dir.create("data")
 dd <- mtcars
 dd$am <- factor(x = dd$am, levels = c(0,1), labels = c("auto", "man"))
 
+save.dta13(dd, "data/dta_121.dta", version = 121, convert.factors = TRUE)
+save.dta13(dd, "data/dta_120.dta", version = 120, convert.factors = TRUE)
 save.dta13(dd, "data/dta_119.dta", version = 119, convert.factors = TRUE)
 save.dta13(dd, "data/dta_118.dta", version = 118, convert.factors = TRUE)
 save.dta13(dd, "data/dta_117.dta", version = 117, convert.factors = TRUE)
@@ -193,6 +201,8 @@ save.dta13(dd, "data/dta_107.dta", version = 107, convert.factors = TRUE)
 # save.dta13(dd, "data/dta_103.dta", version = 103, convert.factors = TRUE)
 # save.dta13(dd, "data/dta_102.dta", version = 102, convert.factors = TRUE)
 
+dd121 <- read.dta13("data/dta_121.dta")
+dd120 <- read.dta13("data/dta_120.dta")
 dd119 <- read.dta13("data/dta_119.dta")
 dd118 <- read.dta13("data/dta_118.dta")
 dd117 <- read.dta13("data/dta_117.dta")
@@ -214,6 +224,8 @@ dd107 <- read.dta13("data/dta_107.dta")
 unlink("data", recursive = TRUE)
 
 test_that("convert.factors TRUE", {
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -243,6 +255,8 @@ dir.create("data")
 dd <- mtcars
 dd$am <- factor(x = dd$am, levels = c(0,1), labels = c("auto", "man"))
 
+save.dta13(dd, "data/dta_121.dta", version = 121, convert.factors = FALSE)
+save.dta13(dd, "data/dta_120.dta", version = 120, convert.factors = FALSE)
 save.dta13(dd, "data/dta_119.dta", version = 119, convert.factors = FALSE)
 save.dta13(dd, "data/dta_118.dta", version = 118, convert.factors = FALSE)
 save.dta13(dd, "data/dta_117.dta", version = 117, convert.factors = FALSE)
@@ -260,6 +274,8 @@ save.dta13(dd, "data/dta_107.dta", version = 107, convert.factors = FALSE)
 # save.dta13(dd, "data/dta_103.dta", version = 103, convert.factors = FALSE)
 # save.dta13(dd, "data/dta_102.dta", version = 102, convert.factors = FALSE)
 
+dd121 <- read.dta13("data/dta_121.dta")
+dd120 <- read.dta13("data/dta_120.dta")
 dd119 <- read.dta13("data/dta_119.dta")
 dd118 <- read.dta13("data/dta_118.dta")
 dd117 <- read.dta13("data/dta_117.dta")
@@ -285,6 +301,8 @@ dd$am <- dd$am + 1
 unlink("data", recursive = TRUE)
 
 test_that("convert.factors TRUE", {
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -312,6 +330,8 @@ dir.create("data")
 
 dd <- mtcars
 
+save.dta13(dd, "data/dta_121.dta", version = 121, add.rownames = TRUE)
+save.dta13(dd, "data/dta_120.dta", version = 120, add.rownames = TRUE)
 save.dta13(dd, "data/dta_119.dta", version = 119, add.rownames = TRUE)
 save.dta13(dd, "data/dta_118.dta", version = 118, add.rownames = TRUE)
 save.dta13(dd, "data/dta_117.dta", version = 117, add.rownames = TRUE)
@@ -329,6 +349,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104, add.rownames = TRUE)
 save.dta13(dd, "data/dta_103.dta", version = 103, add.rownames = TRUE)
 save.dta13(dd, "data/dta_102.dta", version = 102, add.rownames = TRUE)
 
+dd121 <- read.dta13("data/dta_121.dta", add.rownames = TRUE)
+dd120 <- read.dta13("data/dta_120.dta", add.rownames = TRUE)
 dd119 <- read.dta13("data/dta_119.dta", add.rownames = TRUE)
 dd118 <- read.dta13("data/dta_118.dta", add.rownames = TRUE)
 dd117 <- read.dta13("data/dta_117.dta", add.rownames = TRUE)
@@ -351,6 +373,8 @@ unlink("data", recursive = TRUE)
 
 test_that("add.rownames TRUE", {
   # Check that rownames are identical
+  expect_true(identical(rownames(dd), rownames(dd121)))
+  expect_true(identical(rownames(dd), rownames(dd120)))
   expect_true(identical(rownames(dd), rownames(dd119)))
   expect_true(identical(rownames(dd), rownames(dd118)))
   expect_true(identical(rownames(dd), rownames(dd117)))
@@ -369,6 +393,8 @@ test_that("add.rownames TRUE", {
   expect_true(identical(rownames(dd), rownames(dd102)))
 
   # Check that data is identical
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -399,6 +425,8 @@ dir.create("data")
 
 dd <- mtcars
 
+save.dta13(dd, "data/dta_121.dta", version = 121, data.label = dl)
+save.dta13(dd, "data/dta_120.dta", version = 120, data.label = dl)
 save.dta13(dd, "data/dta_119.dta", version = 119, data.label = dl)
 save.dta13(dd, "data/dta_118.dta", version = 118, data.label = dl)
 save.dta13(dd, "data/dta_117.dta", version = 117, data.label = dl)
@@ -416,6 +444,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104, data.label = dl)
 save.dta13(dd, "data/dta_103.dta", version = 103, data.label = dl)
 # save.dta13(dd, "data/dta_102.dta", version = 102, data.label = dl) # no data label
 
+dd121 <- read.dta13("data/dta_121.dta")
+dd120 <- read.dta13("data/dta_120.dta")
 dd119 <- read.dta13("data/dta_119.dta")
 dd118 <- read.dta13("data/dta_118.dta")
 dd117 <- read.dta13("data/dta_117.dta")
@@ -437,6 +467,8 @@ unlink("data", recursive = TRUE)
 
 test_that("data label", {
   # Check that rownames are identical
+  expect_equal(dl, attr(dd121, "datalabel"))
+  expect_equal(dl, attr(dd120, "datalabel"))
   expect_equal(dl, attr(dd119, "datalabel"))
   expect_equal(dl, attr(dd118, "datalabel"))
   expect_equal(dl, attr(dd117, "datalabel"))
@@ -502,6 +534,8 @@ dd <- data.frame(td = as.Date(td),
                  tm = as.Date(tm),
                  tq = as.Date(tq))
 
+save.dta13(dd, "data/dta_121.dta", version = 121, convert.dates = TRUE)
+save.dta13(dd, "data/dta_120.dta", version = 120, convert.dates = TRUE)
 save.dta13(dd, "data/dta_119.dta", version = 119, convert.dates = TRUE)
 save.dta13(dd, "data/dta_118.dta", version = 118, convert.dates = TRUE)
 save.dta13(dd, "data/dta_117.dta", version = 117, convert.dates = TRUE)
@@ -519,6 +553,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104, convert.dates = TRUE)
 save.dta13(dd, "data/dta_103.dta", version = 103, convert.dates = TRUE)
 save.dta13(dd, "data/dta_102.dta", version = 102, convert.dates = TRUE)
 
+dd121 <- read.dta13("data/dta_121.dta")
+dd120 <- read.dta13("data/dta_120.dta")
 dd119 <- read.dta13("data/dta_119.dta")
 dd118 <- read.dta13("data/dta_118.dta")
 dd117 <- read.dta13("data/dta_117.dta")
@@ -540,6 +576,8 @@ unlink("data", recursive = TRUE)
 
 test_that("convert.dates TRUE", {
   # Check that rownames are identical
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -571,6 +609,8 @@ dd <- data.frame( dat = c(paste(replicate(2046, "a"), collapse = ""),
                           paste(replicate(2046, "b"), collapse = "")),
                   stringsAsFactors = FALSE)
 
+save.dta13(dd, "data/dta_121.dta", version = 121)
+save.dta13(dd, "data/dta_120.dta", version = 120)
 save.dta13(dd, "data/dta_119.dta", version = 119)
 save.dta13(dd, "data/dta_118.dta", version = 118)
 save.dta13(dd, "data/dta_117.dta", version = 117)
@@ -588,6 +628,8 @@ save.dta13(dd, "data/dta_117.dta", version = 117)
 # save.dta13(dd, "data/dta_103.dta", version = 103)
 # save.dta13(dd, "data/dta_102.dta", version = 102)
 
+dd121 <- read.dta13("data/dta_121.dta", replace.strl = TRUE)
+dd120 <- read.dta13("data/dta_120.dta", replace.strl = TRUE)
 dd119 <- read.dta13("data/dta_119.dta", replace.strl = TRUE)
 dd118 <- read.dta13("data/dta_118.dta", replace.strl = TRUE)
 dd117 <- read.dta13("data/dta_117.dta", replace.strl = TRUE)
@@ -609,6 +651,8 @@ unlink("data", recursive = TRUE)
 
 test_that("replace.strl TRUE", {
   # Check that rownames are identical
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -636,6 +680,8 @@ dir.create("data")
 
 dd <- data.frame(x.1 = 1)
 
+save.dta13(dd, "data/dta_121.dta", version = 121, convert.underscore = TRUE)
+save.dta13(dd, "data/dta_120.dta", version = 120, convert.underscore = TRUE)
 save.dta13(dd, "data/dta_119.dta", version = 119, convert.underscore = TRUE)
 save.dta13(dd, "data/dta_118.dta", version = 118, convert.underscore = TRUE)
 save.dta13(dd, "data/dta_117.dta", version = 117, convert.underscore = TRUE)
@@ -653,6 +699,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104, convert.underscore = TRUE)
 save.dta13(dd, "data/dta_103.dta", version = 103, convert.underscore = TRUE)
 save.dta13(dd, "data/dta_102.dta", version = 102, convert.underscore = TRUE)
 
+dd121 <- read.dta13("data/dta_121.dta")
+dd120 <- read.dta13("data/dta_120.dta")
 dd119 <- read.dta13("data/dta_119.dta")
 dd118 <- read.dta13("data/dta_118.dta")
 dd117 <- read.dta13("data/dta_117.dta")
@@ -676,6 +724,8 @@ names(dd) <- "x_1"
 
 test_that("convert.underscore TRUE", {
   # check numerics
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -693,6 +743,8 @@ test_that("convert.underscore TRUE", {
   expect_true(datacompare(dd, dd103))
   expect_true(datacompare(dd, dd102))
   # check names
+  expect_true(namescompare(dd, dd121))
+  expect_true(namescompare(dd, dd120))
   expect_true(namescompare(dd, dd119))
   expect_true(namescompare(dd, dd118))
   expect_true(namescompare(dd, dd117))
@@ -720,6 +772,8 @@ dir.create("data")
 
 dd <- mtcars
 
+save.dta13(dd, "data/dta_121.dta", version = 121)
+save.dta13(dd, "data/dta_120.dta", version = 120)
 save.dta13(dd, "data/dta_119.dta", version = 119)
 save.dta13(dd, "data/dta_118.dta", version = 118)
 save.dta13(dd, "data/dta_117.dta", version = 117)
@@ -737,6 +791,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104)
 save.dta13(dd, "data/dta_103.dta", version = 103)
 save.dta13(dd, "data/dta_102.dta", version = 102)
 
+dd121 <- read.dta13("data/dta_121.dta", select.rows = 5)
+dd120 <- read.dta13("data/dta_120.dta", select.rows = 5)
 dd119 <- read.dta13("data/dta_119.dta", select.rows = 5)
 dd118 <- read.dta13("data/dta_118.dta", select.rows = 5)
 dd117 <- read.dta13("data/dta_117.dta", select.rows = 5)
@@ -760,6 +816,8 @@ dd <- dd[1:5,]
 
 test_that("select.rows = 5", {
   # check numerics
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -784,6 +842,8 @@ dir.create("data")
 
 dd <- mtcars
 
+save.dta13(dd, "data/dta_121.dta", version = 121)
+save.dta13(dd, "data/dta_120.dta", version = 120)
 save.dta13(dd, "data/dta_119.dta", version = 119)
 save.dta13(dd, "data/dta_118.dta", version = 118)
 save.dta13(dd, "data/dta_117.dta", version = 117)
@@ -801,6 +861,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104)
 save.dta13(dd, "data/dta_103.dta", version = 103)
 save.dta13(dd, "data/dta_102.dta", version = 102)
 
+dd121 <- read.dta13("data/dta_121.dta", select.rows = c(5,10))
+dd120 <- read.dta13("data/dta_120.dta", select.rows = c(5,10))
 dd119 <- read.dta13("data/dta_119.dta", select.rows = c(5,10))
 dd118 <- read.dta13("data/dta_118.dta", select.rows = c(5,10))
 dd117 <- read.dta13("data/dta_117.dta", select.rows = c(5,10))
@@ -824,6 +886,8 @@ dd <- dd[5:10,]
 
 test_that("select.rows = c(5,10)", {
   # check numerics
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -852,6 +916,8 @@ dir.create("data")
 
 dd <- mtcars
 
+save.dta13(dd, "data/dta_121.dta", version = 121)
+save.dta13(dd, "data/dta_120.dta", version = 120)
 save.dta13(dd, "data/dta_119.dta", version = 119)
 save.dta13(dd, "data/dta_118.dta", version = 118)
 save.dta13(dd, "data/dta_117.dta", version = 117)
@@ -869,6 +935,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104)
 save.dta13(dd, "data/dta_103.dta", version = 103)
 save.dta13(dd, "data/dta_102.dta", version = 102)
 
+dd121 <- read.dta13("data/dta_121.dta", select.cols = c("disp", "drat"))
+dd120 <- read.dta13("data/dta_120.dta", select.cols = c("disp", "drat"))
 dd119 <- read.dta13("data/dta_119.dta", select.cols = c("disp", "drat"))
 dd118 <- read.dta13("data/dta_118.dta", select.cols = c("disp", "drat"))
 dd117 <- read.dta13("data/dta_117.dta", select.cols = c("disp", "drat"))
@@ -892,6 +960,8 @@ dd <- dd[,c("disp", "drat")]
 
 test_that("select.cols = c('disp', 'drat')", {
   # check numerics
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -916,6 +986,8 @@ dir.create("data")
 
 dd <- mtcars
 
+save.dta13(dd, "data/dta_121.dta", version = 121)
+save.dta13(dd, "data/dta_120.dta", version = 120)
 save.dta13(dd, "data/dta_119.dta", version = 119)
 save.dta13(dd, "data/dta_118.dta", version = 118)
 save.dta13(dd, "data/dta_117.dta", version = 117)
@@ -933,6 +1005,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104)
 save.dta13(dd, "data/dta_103.dta", version = 103)
 save.dta13(dd, "data/dta_102.dta", version = 102)
 
+dd121 <- read.dta13("data/dta_121.dta", select.cols = c(3, 5))
+dd120 <- read.dta13("data/dta_120.dta", select.cols = c(3, 5))
 dd119 <- read.dta13("data/dta_119.dta", select.cols = c(3, 5))
 dd118 <- read.dta13("data/dta_118.dta", select.cols = c(3, 5))
 dd117 <- read.dta13("data/dta_117.dta", select.cols = c(3, 5))
@@ -956,6 +1030,8 @@ dd <- dd[,c("disp", "drat")]
 
 test_that("select.cols = c('disp', 'drat')", {
   # check numerics
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))
@@ -1010,6 +1086,8 @@ ef <- list(
 
 attr(dd, "expansion.fields") <- ef
 
+save.dta13(dd, "data/dta_121.dta", version = 121)
+save.dta13(dd, "data/dta_120.dta", version = 120)
 save.dta13(dd, "data/dta_119.dta", version = 119)
 save.dta13(dd, "data/dta_118.dta", version = 118)
 save.dta13(dd, "data/dta_117.dta", version = 117)
@@ -1027,6 +1105,8 @@ save.dta13(dd, "data/dta_105.dta", version = 105)
 # save.dta13(dd, "data/dta_103.dta", version = 103)
 # save.dta13(dd, "data/dta_102.dta", version = 102)
 
+dd121 <- attr(read.dta13("data/dta_121.dta"), "expansion.fields")
+dd120 <- attr(read.dta13("data/dta_120.dta"), "expansion.fields")
 dd119 <- attr(read.dta13("data/dta_119.dta"), "expansion.fields")
 dd118 <- attr(read.dta13("data/dta_118.dta"), "expansion.fields")
 dd117 <- attr(read.dta13("data/dta_117.dta"), "expansion.fields")
@@ -1048,6 +1128,8 @@ unlink("data", recursive = TRUE)
 
 test_that("expansinon.fields", {
   # check numerics
+  expect_equal(ef, dd121)
+  expect_equal(ef, dd120)
   expect_equal(ef, dd119)
   expect_equal(ef, dd118)
   expect_equal(ef, dd117)
@@ -1077,8 +1159,8 @@ dd <- mtcars
 varlabeldd <- LETTERS[seq_len(ncol(dd))]
 varlabel(dd) <- varlabeldd
 
-version_list <- c(102,103,104,105,106,107,108,110,
-                  111,112,113,114,115,117,118,119)
+version_list <- c(102,103,104,105,106,107,108,110,111,
+                  112,113,114,115,117,118,119,120,121)
 
 # write variable label attribute
 for(v in version_list) {
@@ -1113,6 +1195,8 @@ dir.create("data")
 dd <- data.frame(x1 = c("NA", NA_character_))
 exp <- data.frame(x1 = c("NA", ""))
 
+save.dta13(dd, "data/dta_121.dta", version = 121)
+save.dta13(dd, "data/dta_120.dta", version = 120)
 save.dta13(dd, "data/dta_119.dta", version = 119)
 save.dta13(dd, "data/dta_118.dta", version = 118)
 save.dta13(dd, "data/dta_117.dta", version = 117)
@@ -1130,6 +1214,8 @@ save.dta13(dd, "data/dta_104.dta", version = 104)
 save.dta13(dd, "data/dta_103.dta", version = 103)
 save.dta13(dd, "data/dta_102.dta", version = 102)
 
+dd121 <- read.dta13("data/dta_121.dta")
+dd120 <- read.dta13("data/dta_120.dta")
 dd119 <- read.dta13("data/dta_119.dta")
 dd118 <- read.dta13("data/dta_118.dta")
 dd117 <- read.dta13("data/dta_117.dta")
@@ -1148,6 +1234,8 @@ dd103 <- read.dta13("data/dta_103.dta")
 dd102 <- read.dta13("data/dta_102.dta")
 
 test_that("NA character works", {
+  expect_true(datacompare(exp, dd121))
+  expect_true(datacompare(exp, dd120))
   expect_true(datacompare(exp, dd119))
   expect_true(datacompare(exp, dd118))
   expect_true(datacompare(exp, dd117))
@@ -1178,15 +1266,21 @@ dd <- data.frame( dat = c(paste(replicate(2046, "a"), collapse = ""),
                           "NA", NA_character_),
                   stringsAsFactors = FALSE)
 
+save.dta13(dd, "data/dta_121.dta", version = 121)
+save.dta13(dd, "data/dta_120.dta", version = 120)
 save.dta13(dd, "data/dta_119.dta", version = 119)
 save.dta13(dd, "data/dta_118.dta", version = 118)
 save.dta13(dd, "data/dta_117.dta", version = 117)
 
+dd121 <- read.dta13("data/dta_121.dta")
+dd120 <- read.dta13("data/dta_120.dta")
 dd119 <- read.dta13("data/dta_119.dta")
 dd118 <- read.dta13("data/dta_118.dta")
 dd117 <- read.dta13("data/dta_117.dta")
 
 test_that("NA character works", {
+  expect_true(datacompare(dd, dd121))
+  expect_true(datacompare(dd, dd120))
   expect_true(datacompare(dd, dd119))
   expect_true(datacompare(dd, dd118))
   expect_true(datacompare(dd, dd117))