+ Additionally, it is now possible to define configuration/platform-
+ specific names (called "system identities"). In the C code, these
+ are prefixed with "OPENSSL_SYSNAME_". e_os2.h will create another
+ macro with the name beginning with "OPENSSL_SYS_", which is determined
+ from "OPENSSL_SYSNAME_*" or compiler-specific macros depending on
+ what is available.