> The choice depends on whether the word that comes after starts with a vowel or not
Or an aitch / h, but only sometimes.
Or an aitch / h, but only sometimes.
That's the opposite of how it works (as you demonstrated in your own comment, "not a rule...")
The comment you responded to was correct, or at least very reasonable, and I'm really not sure which part you disagree with.
There's a few words in English that begin with the letter h but not with the consonant sound /h/ (depending on your accent!), mostly because they're French in origin: historic is one, and there's also hour, heir, honour. "It is an honour to be here"
It's silly to act like there's a right or wrong. Dialects and accents are a special thing. Just be consistent.
Solution get rid of article. Someone want to know if thing is definitive thing, can figure it out from context!
(also, I'm in the opposite superstate to the one you are in -- both "a SQL parser" and "an SQL parser" look fine to me, although I internally pronounce the first as "a seekwul parser" and the second as "an ess cue ell parser")
a sequel parser is also fine *
* my old Unix colleagues will remember that Sequel is a brand of database that nobody else remembers anymore so tended to use the initialism.