--- libgig/trunk/man/wav2gig.1.in	2021/09/02 16:22:36	3994
+++ libgig/trunk/man/wav2gig.1.in	2021/09/03 15:06:10	3995
@@ -1,4 +1,4 @@
-.TH "wav2gig" "1" "02 Sep 2021" "libgig @VERSION@" "libgig tools"
+.TH "wav2gig" "1" "03 Sep 2021" "libgig @VERSION@" "libgig tools"
 .SH NAME
 wav2gig \- Create GigaStudio (.gig) file from a set of WAV files.
 .SH SYNOPSIS
@@ -19,8 +19,8 @@
 GigaStudio (.gig) file and tries to automatically map the samples in a
 meaningful way to that instrument. As the wave (.wav) format currently does not
 support many of the meta information required for this particular task, this
-tool tries to guess the required information from the individual sample's name
-for mapping the samples accordingly. See
+tool tries to extract the required (missing) information from the individual
+sample's file name for being able to map the samples accordingly. See
 .BR SAMPLE
 .BR NAMES
 below for details on the assumed naming scheme for input sample files and how
@@ -158,6 +158,46 @@
 .BR --regex-note-name
 to override this part of the naming scheme.
 
+.PP
+This tool utilizes the
+.I regular expressions
+library provided by C++ (introduced with the C++11 standard revision).
+Each custom regular expression (abbreviated as 'RegEx' from now on below)
+passed to one of the 
+.BR --regex-*
+options must contain
+.B
+exactly one
+active RegEx 'capture group' which is denoted in regular expressions by a pair
+of round brackets like:
+
+.B (PATTERN)
+
+So the 'capture group' marks the portion in the overall filename string that is
+going to be exctracted for the respective component of the filename schema.
+If additional RegEx group(s) are needed to build the overall RegEx pattern, then
+those other group(s) must be defined as 'passive groups' denoted in RegEx
+patterns by an additional question mark and colon like this:
+
+.B (?:PATTERN)
+
+Keep in mind that RegEx scanners behave 'greedy' by default, which means by
+default they try to match the longest string possible according to your defined
+RegEx pattern. If that's not desired then you may either override the required
+parts of your RegEx pattern to behave 'non-greedy' such that those parts would
+match for the shortest string possible instead, or alternatively consider using
+the RegEx 'alternation'
+operator, which is denoted in regular expressions by a vertical bar character
+like:
+
+.B PATTERN1|PATTERN2|PATTERN3
+
+The RegEx 'alternation' operator is sometimes more intuitive, because it tries
+to match the provided patterns strictly in order from left to right. So it
+would first try to match the first pattern, and only if no match with the first
+pattern was possible (independent of string length) it would then try to match
+the second pattern, and so on.
+
 .SH "SEE ALSO"
 .BR gig2mono(1),
 .BR gigextract(1),