de8fd92a_Advanced_Typography_tables__Reading_support
[0] 3 [name] cursive attachment [Writing support] Only the 'curs' feature is supported for this sub-table. These may be created with the Points->Add Anchor command [Reading support] 
This sub-table allows the font designer to force adjacent glyphs to join at specific points. It can be used to generate the slanted script style needed for Urdu.
Advanced Typography tables
Reading support