As far as I tested applications (latest Thunderbird, Firefox, Seamonkey, OpenOffice.org versions) that use Hunspell as backend for their spellchecker, any compound word that includes "%" and "+25" symbols, and is made by other words included in a dictionary, are seen as correct.
Example:
bug%test
bug+25test
I don't think there's any language in the world that utilize such symbols as word breaker.