{not available when compiled without the |+find_in_path| feature} Pattern to be used to find an include command. It is a search pattern, just like for the "/" command (See |pattern|). The default value is for C programs. This option is used for the commands "[i", "]I", "[d", etc. Normally the 'isfname' option is used to recognize the file name that comes after the matched pattern. But if "\zs" appears in the pattern then the text matched from "\zs" to the end, or until "\ze" if it appears, is used as the file name. Use this to include characters that are not in 'isfname', such as a space. You can then use 'includeexpr' to process the matched text. See |option-backslash| about including spaces and backslashes.