-@GNUTAR{} versions up to 1.15.1. The second format, called @dfn{format
-1} is an extended version of this format, that contains more metadata
-and allows for further extensions. It was used by version
-1.15.1. Starting from version 1.16 and up to @value{VERSION}, the
-@dfn{format 2} is used.
+@GNUTAR{} versions up to and including 1.15.1. The second format, called
+@dfn{format 1} is an extended version of this format, that contains more
+metadata and allows for further extensions. It was used by alpha release
+version 1.15.90. For alpha version 1.15.91 and stable releases
+version 1.16 up through @value{VERSION}, the @dfn{format 2} is used.