This is still wonderfully relevant. However, we now believe the vertical juxtaposition indicator (GTM 14.3.3) should be used in transcribing "question mark over equals sign."
APH's UEB Math Tutorial describes this method for transcribing a "question mark appears directly above the equal sign in print" in its Lesson 6.7.
So, what I would recommend for ≟ is ;;8]"7
The vertical juxtaposition indicator (instead of the directly above indicator) more accurately communicates the intent of the symbol ≟, because it lets the question mark and the equals sign have separate meanings instead of making the equals sign's meaning be "modified" by the question mark.
This reply was modified 12 months ago by kdejute.
This reply was modified 12 months ago by kdejute. Reason: correct simbraille
This reply was modified 12 months ago by kdejute. Reason: add grade 1 symbol indicator before question mark at the beginning of a symbols-sequence
This reply was modified 11 months, 3 weeks ago by kdejute. Reason: used grade 1 word indicator instead of multiple grade 1 symbol indicators