MPLAB® XC8 compilers use a default length of 255 significant characters in C identifier (As per the standard minimum value should be 31 characters).
The -N option, represented by the Identifier length field in the Compiler node of the Compiler Build Options dialog, can be used to change the identifier length to anywhere between 31 and 255 characters.
This option also controls the length of macro names used by the C preprocessor, which also have a default length of 31.
The assembler has no specific limit on identifier lengths — all characters are significant, and the line length is the only limitation (typically 256 characters or more).
Whatever the length of a identifier, the linker preserves the full name. Symbols are case-sensitive in all situations.