Special characters

If the option evaluate special characters is tagged, some characters will have a special meaning when used in a search expression. Use these characters in an appropriate way and take advantage of a mighty look-up function.
The full stop represents any character.
[ ]
Characters within square brackets represent all these characters but no other ones.
represents Maus or Mäus and finds words like Maus, Mäuse and Mäuschen.
[^ ]
A ^ (caret) at the beginning of a string enclosed in square brackets corresponds to a logic not.
represents any character but u, v, or w.
Square brackets cannot be nested.
[ - ]
A hyphen within square brackets indicates a character scope. The character in front of the - (hyphen) must be smaller than the one behind it.
represents überbea to überbem.
represents essentially überben to überbez.
( | )
Round brackets can be used to indicate alternative strings.
represents laufen or rennen.
represents laufen or rennen or gehen.
represents ausgeben or ausgegeben.
Square brackets may be used within round brackets but not vice versa.
Round brackets cannot be nested.
A ? (question mark) behind a character means that it is optional. You also can insert it after a closing bracket. In that case it would effect the whole character class.
represents color or colour.
file[\- ]?proof
represents fireproof, fire-proof, or fire proof. Please note that since the hyphen resides within square brackets it needed to be quoted with the preceding back slash to look it up.
is identical to ausge(ge|)ben and represents ausgeben or ausgegeben.
Among others, this expression represents know, knew, or known and will find exactly these words if both word boundary options are tagged. Otherwise the suffix n? were wasted and words like knowing would be found, too.
Using a question mark within square brackets is not allowed.
A back slash quotes the following character, i.e. the special property of the following character, if at all it is a special character, will be ignored.
represents ? (the question mark).
If evaluate special chars is activated, all special characters, except for - (hyphen) and ^ (caret) outside of square brackets, must always be quoted with a back slash to search for them.