Chapter 8. Symbols

8.1. C Reference
ecl_make_keyword — Find a lisp keyword
ecl_make_symbol — Find a lisp symbol
ANSI Dictionary — Common Lisp and C equivalence

There are no implementation-specific limits on the size or content of symbol names. It is however not allowed to write on the strings which have been passed to #'make-symbol or returned from #'symbol-name.

8.1. C Reference