2.1.34 Part 1 Section 15.2.12, Font Part
a. The standard states that fonts are stored in one of two formats: application/x-fontdata and application/x-font-ttf, which does not account for the obfuscation in WordprocessingML documents.
Word stores obfuscated fonts using the following content type: application/vnd.openxmlformats-officedocument.obfuscatedFont. application/vnd.openxmlformats-officedocument.obfuscatedFont specifies that the font shall be stored in the TrueType or OpenType format and shall be obfuscated using the algorithm specified by Font Embedding ("[ECMA-376] Part 4 §2.8.1; Font Embedding"). Only WordprocessingML is permitted to reference obfuscated fonts.
This note applies to the following products: 2007, 2007 SP1, 2007 SP2.
b. The standard states that application/x-font-ttf specifies that the font shall be stored in the TrueType or OpenType format.
PowerPoint does not use this content type. Word reads these fonts if the value of the fontKey attribute is equal to 00000000-0000-0000-0000-000000000000.
c. The standard states that application/x-fontdata specifies that the font shall be stored as a bitmapped font (each glyph is stored as a raster image).