 a <a href="https://www.microsoft.com/typography/otspec/features_ko.htm#mark"
  >Mark Positioning</a> feature in
  its <a href="https://www.microsoft.com/typography/otspec/gpos.htm">Glyph
  Positioning</a> table. The feature uses
  a <a href="https://www.microsoft.com/typography/otspec/gpos.htm#MBP"
  >MarkToBase Attachment Positioning Subtable</a> for placing Ethiopic
  diacritics on top of a base glyph.  If your text rendering engine is
  correct, the dots (which indicate <em>“long vowel”, “long
  c