DBCS identifiers can be composed of single-byte characters in DBCS form, double-byte characters, or a combination of both.
DBCS identifiers containing only single-byte characters must conform to the normal PL/I naming conventions, including the first-character rule. A DBCS identifier containing single-byte characters expressed as DBCS equivalents is a synonym of the same identifier in SBCS.
Example:
<.I.B.M> = 3; /* is the same as IBM=3; */
The number of bytes used in a DBCS name cannot exceed the value specified as the maximum length of a name specified in the compiler LIMITS option.
SBCS characters expressed in DBCS form within a DBCS identifier are considered to be SBCS, for example:
A<kk>B A<kk.B> <.Akk>B /* are all A<kk>B (SBCS-DBCS-SBCS) */
A DBCS identifier can be used wherever an SBCS identifier is allowed. When DBCS identifiers are used for EXTERNAL names and %INCLUDE file names, you must ensure that the identifiers are acceptable to the operating system, or are made acceptable by one of the following: