Initials are not bound by the laws of grammar. Most are constructed to roll off the tongue or even form a word (acronym). For this purpose, articles, prepositions etc and even syllables can have their letters used or not as the case may be to give the desired effect.
PTF ARCO MDF and my favorite ... BF`A .. (big flippin `ammer ...) Not forgetting .. BSA NSU DOT KTM JAWA SOLEX BMW MV etc etc
My favourite is DILLIGAF Do I look like I give away fishfingers? (said in exasperation when I worked on the checkout in the local Co-op and some joker would ask for free Findus products)
Am I the only person reading this that concludes hardly anyone has actually read and understood the original posters point. Lines, after school, all of you (and I don't mean coke)