tn12

Could you specify what domain or context you want for "tn12"? The term can refer to several different things across fields such as firearms (a model or variant of a 12 gauge shell), technology or software (a file format, protocol, or project code), or other topics. If you provide the intended context or a brief description of what tn12 represents for you, I can generate a concise wiki-style article under 300 words.