ffap-string-at-point-mode-alist

ffap-string-at-point-mode-alist is a variable defined in `ffap.el'.
Its value is

((file "--:\\\\$+<>@-Z_[:alpha:]~*?" "<@" "@>;.,!:")
 (url "--:=&?$+@-Z_[:alpha:]~#,%;*()!'" "^[0-9a-zA-Z]" ":;.,!?")
 (nocolon "--9$+<>@-Z_[:alpha:]~" "<@" "@>;.,!?")
 (machine "-[:alnum:]." "" ".")
 (math-mode ",-:$+<>@-Z_[:lower:]~`" "<" "@>;.,!?`:"))

• This variable may be risky if used as a file-local variable.

Documentation:
Alist of (MODE CHARS BEG END), where MODE is a symbol,
possibly a major-mode name, or one of the symbols
`file', `url', `machine', and `nocolon'.
Function `ffap-string-at-point' uses the data fields as follows:
1. find a maximal string of CHARS around point,
2. strip BEG chars before point from the beginning,
3. strip END chars after point from the end.