Total Commander

I suggest to move the information about the used software library on the help page "Regular expressions" to the top.

Many users don't reach the end of the help page and miss the link to the library's webpage, which contains a clear and more extensive explanation of supported regular expressions, and in multiple languages.

Also, TC's help page calls the library a free Delphi library, while the website says:

TRegExpr is implemented in pure Pascal. It's included into Lazarus (Free Pascal): package. But also it exists as separate library and can be compiled by Delphi 2-7, Borland C++ Builder 3-6.

Perhaps it used to be a Delphi library, but the current maintainer and the current main contributors don't even have Delphi. So perhaps it's better to replace "Delphi" with "Pascal".

Currently the page starts with:

Regular expressions are a very powerful search tool. They allow to search for complex classes of words. Regular expressions are mainly meant for professionals, but can also be useful in the office for finding certain documents (see examples below).

I suggest to remove the text "(see examples below)" and add the information about the used library below it. For example like this:

Regular expressions are a very powerful search tool. They allow to search for complex classes of words. Regular expressions are mainly meant for professionals, but can also be useful in the office for finding certain documents.

Total Commander uses the free Pascal library TRegExpr by Andrey V. Sorokin, available at https://regex.sorokin.engineer. Some of the explanations on this page are taken from the help file for this library.

Side note:
Perhaps using a newer version of the library could be considered. The library has undergone several changes and one notable change is the addition \K, which provides a convenient way to exclude the text matched before \K from the final match result.