6.10. Standards [ALL] [ANSI] [DEFAULT] [NONE] [SAA] [TRL1] REXX Language level 3.50, as described in [TRL1]. [TRL2] REXX Language level 4.00, as described in [TRL2]. Also, for those of these standards that have a accepted REXX language level number, that number can be used, provided that it matches character by character (i.e. not by numeric value). Thus, you can use 3.50 as a synonym for TRL1, and 4.00 as a synonym for TRL2. Option ALL ANSI DEF NONE SAA TRL1 TRL2 BUFTYPE_B yes ?? yes no ?? no no IF CLOSE_BIF yes ?? yes no ?? no no CACHEEXT no no no no no no no DESBUF_BI yes ?? yes no ?? no no F DROPBUF_B yes ?? yes no ?? no no IF FIND_BIF yes ?? yes no ?? no no FLUSHSTAC yes ?? no no ?? no no K LINEOUTTR yes ?? yes no ?? no no UNC MAKEBUF_B yes ?? yes no ?? no no IF OPEN_BIF yes ?? yes no ?? no no PRUNE_TRA yes no yes no no no no CE UPPER_CLA yes ?? yes no ?? no no USE Note that the standard and default interpreter is a REXX language level 4.00 interpreter. All other functionality is extensions. In fact, the features in 4.00 that does not exist in 3.50 are “inverse” extensions, i.e. the extension is to remove the functionality only in 4.00.