This format (often starting with ! ) is commonly used in Usenet headers or automated posting scripts to index specific files.
That string looks like a for a compressed archive, but it’s a bit ambiguous. Depending on where you saw it, it could mean a few different things: !XDAB_(129).rar
Could you let me know where you found this or what you are trying to do with it? For example, are you trying to a file with this name, or This format (often starting with