I am trying to figure out this issue:
Does Mark to Mark feature, depends on Mark to Base feature?I thought that the answer is "NO!" - so if I leave the marks with no Mark to Base definition, it will stand at the end of the Base glyph, and if it followed by another mark, that has 'mkmk' - this offset will take place.
But i've got confused while checking it:
1. Mark to Base + Mark to MarkThis is what shows on FontCreator preview:

And it comes out just fine on InDesign:
2. Mark to Mark (with no Mark to Base)
It looks like it is working on FontCreator preview:

But it does not work on InDesign:

I will really appreciate your kind and clever help on this issue!
[Note: on the DirectWrite shape engine it does not work, but on HarfBuzz it works]
Comments
Hebrew is something of a special case: if mark-to-base is not provided, layout may fall back to a legacy Hebrew mark positioning algorithm, which will centre the marks on the advance width of the base, which is what might be happening here.
That seems to be the right answer! Great thanks!
Could not find the exact documentation for that - and it will be more than helpful if you can show me a specific link for that! (is it HERE?)
Did You check if "Diacritic Positioning" is set "opentype" in all text?
Sami