In inputs.conf and props.conf, the wildcards ... and * are supported for use in the spec headers. What do they translate to in PCRE? This is useful to know because sometimes the resulting matches are confusing.
...(three periods) in source stanza headings is treated as
.*in PCRE regex
*(asterisk) in source stanza headings is treated as
[^/\\]*in PCRE regex
.(one period) in stanza headings is treated as
^at the beginning and an implicit
$at the end, and that must match the source value.
BTW, a particular piece of PCRE regex that may be particularly useful is the prefix
(?i), which indicates that the regex from that point on is case-insensitive. This should usually be used when trying to match Windows file paths, e.g.,