Arabic marks assigned to bases

Excuse me, I am abeginner and I want to know how to assign all the above combining marks to all letters and all the below marks to all letters

Please take a look in the Tutorials. There is an article about Arabic and a article about mark attachment, and many more resources to help you get started.

Thank you for quick reply
I mean that some letters have certain mark to be assigned with … I want to assign all the marks for every letter. Should I modify the XML data file ? It will take along time to do that , is there any easier method ?

What do you mean by assigned?

I mean all marks will be positioned on all letters in the mark feature

I mean also the mark cloud is all the combining marks not only that in the XML file

This already works. Just make sure your anchors are in place.

This is something else. If you want a mark cloud preview with all marks in Glyphs, then you have to edit the Glyph Data XML. There is a tutorial about it.

How to edit the XML file