completion-regexp-listcompletion-regexp-list is a variable defined in `
C source code'. Its value is
nilDocumentation: List of regexps that should restrict possible completions. The basic completion functions only consider a completion acceptable if it matches all regular expressions in this list, with `case-fold-search' bound to the value of `completion-ignore-case'. See Info node `(elisp)Basic Completion', for a description of these functions.