Using "R" to mark vowel length

Question

When messaging a British colleague, I noticed something interesting in the orthography. Where I would write "she killed" as necāvit, she writes necarvit.

In a non-rhotic accent, this makes perfect sense: ar in this environment is a longer version of a, and it can be typed on an English keyboard more easily than ā can.

But I'm curious: is this any sort of official or common practice? Or is it an accident of the sort the Appendix Probī hates so much, replacing one spelling with another that sounds identical?

(My accent, by comparison, is rhotic: I pronounce the r there as a consonant, which makes it sound completely different.)

Answer 1

I don't know of any way of interpreting "necarvit" other than as a simple spelling error.

The usual way of typing a Latin long a in the ASCII character set would be "a". Classical Latin writing did not consistently mark vowel length, and this feature of the Latin writing system has continued to the present day. When people want to mark length in the Latin spelling system, they use macrons, or less commonly, apices. Disambiguation is rarely necessary for successful communication: there is no necăvit to confuse with necāvit.

Even for a non-rhotic speaker of British English, "R" would not a be particularly natural way to write vowel length for most vowels: British English speakers tend to pronounce <er>, <ir>, <ur> as [ɜː~əː] in stressed syllables, or as [ə] in unstressed syllables (or as [ɛɹ, ɪɹ, ʌɹ] when followed by a vowel within the same word, although that is an uncommon context for Latin long vowels).