The description of displayOperatorMinHeight has:

Minimum height of n-ary operators (such as integral and summation) for formulas in display mode (that is, appearing as standalone page elements, not embedded inline within text).

But it has long been a source of trouble since Cambria Math sets it to a value that when respected results in too small display operators being selected: w3c/mathml-core#126

My own testing shows that Microsoft Word does not use displayOperatorMinHeight at all (setting it to any value makes no difference in which size of display operators is selected) and instead it seems to use the value of delimitedSubFormulaMinHeight to select the display operators size.

I’m speculating here, but I think it is a bug in Microsoft implementation and the wrong value in Cambria Math went unnoticed because of it.

I’m not sure what the spec should do here, but may be at least Cambria Math should be updated to use a reasonable displayOperatorMinHeight so that implmentations that follow the spec don’t have to implement various workarounds that render displayOperatorMinHeight almost useless.

Document Details

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• ID: f0076fd2-52b0-2989-3142-fd9e456b9514
• Version Independent ID: 4aef8fa3-2ad3-7933-5a77-0a7473e66112
• Content: MATH - The mathematical typesetting table (OpenType 1.9) - Typography
• Content Source: typographydocs/opentype/spec/math.md
• Service: typography
• GitHub Login: @PeterCon
• Microsoft Alias: alib