A MarkToMarkAdjustmentRecord defines the positional adjustment between a base mark glyph and combining mark glyph.
| baseMarkGlyphAnchorPoint | The position of the anchor point of the base mark glyph. | 
| baseMarkGlyphID | The index of the base mark glyph. | 
| combiningMarkGlyphID | The index of the combining mark glyph. | 
| combiningMarkPositionAdjustment | The positional adjustment of the combining mark glyph relative to the anchor point of the base mark glyph. |