According to the first definition found in most dictionaries, examples of acronyms are NATO (/ˈneɪtoʊ/), scuba (/ˈskuːbə/), and radar (/ˈreɪdɑr/), while examples of initialisms are FBI (/ˌɛfˌbiːˈaɪ/) and HTML (/ˌeɪtʃˌtiːˌɛmˈɛl/). - source wiki
Initialisms are pronounced letter by letter using the alphabet character's names. Acronyms are read and treated as words.
Since Baybayin is an Abugida and each of its characters are phonetic syllables, Filipino acronyms and initialisms should be written in Baybayin script as they are pronounced in Filipino.
Since "acronyms are read and treated as words" and a lot of acronyms are "names" of organizations and technical terminology, we then go back to the "rules of thumb" which are:
- If the word is an important scientific or technical term and you do not have a direct and official translation to any Philippine language or Spanish - don't Pilipinize the spelling and don't write it in Baybayin Script, use the Latin Alphabet instead.
- If the word is a name of person (or organization) - don't Pilipinize the spelling and don't write it in Baybayin Script, use the Latin Alphabet instead - unless if that person (or group) made known to you or the public how they write his/her name in Baybayin (or they personally requested you to do so); how one prefers their name spelled & pronounced is a personal issue.
One may argue that the acronym for "Unibersidad ng Pilipinas", UP (/ʊpɪ/) should have been written as ᜂᜉᜒ which is read as "upi" and not as ᜂᜉ which is read as "upa" as shown in their graduation sash.
"The indigenous letters ᜂ and ᜉ , originating from the indigenous alphabet called baybayin or katitikan, are equivalent to the Roman letters “U” and “P”, respectively."Note: They used the terms - indigenous "letters", indigenous "alphabet", and "equivalent to Roman letters" to describe Baybayin Script. A clue?
Baybayin is NOT an Alphabet.
It's quite possible that they were not aware that Baybayin was already described in detail in numerous publications from earlier on as a "syllabary". While the terms "abugida" and "alpha-syllabary" distinctions are more recent, nevertheless, Baybayin still is classified linguistically as a syllabary. But as a center and authority for higher learning, this failure to recognize the well established details about Baybayin does not sit well with many researchers and practitioners in the Baybayin support community.
There is nothing we can do with the UPa issue at the moment, only they can resolve that.
Meanwhile, a couple of Baybayin enthusiasts have suggested to either use a virama or make up a new mark that has the function of changing a baybayin character to its equivalent alphabet letter name.
As far as using a virama; we must bear in mind that if you cancel the inherent /a/ vowel of a Baybayin (Abugida) character, you end up with a consonant 'sound' particle not a consonant letter name. A ᜋ᜔ ('Ma' with a virama) or ᜋ᜴ ('Ma' with a pamudpud) is not an 'M' pronounced as /ɛm/, it is a /m/ sound. Such is the assigned function of a virama mark.
So with that in mind, why not make up a new mark and instead of calling it a virama, call it something like maybe a "tari" mark, right? The new mark they introduced looks like a mix of an x-virama & a pamudpod. This new mark is assigned the function of changing a Baybayin character to its equivalent Alphabet letter name. It seems like a good idea, but it is a long way from being linguistically or officially recognized or standardized & approved. It also still has the problem of finding equivalents for the letters C, J, Q, and X, etc.
For now, it's best we just follow the "rules of thumb".