Adobe NotDef is a special-purpose OpenType font that is based on the Adobe-Identity-0 ROS (ROS stands for /Registry, /Ordering, and /Supplement, and refers to the /CIDSystemInfo dictionary entries that define the glyph set name for CID-based character collections). The Adobe-Identity-0 ROS is a special-purpose character collection whose use is not tied to a specific language, and Adobe NotDef is a special-purpose OpenType font that is intended to render all Unicode code points using a very obvious .notdef glyph, thus the reason why the Adobe-Identity-0 ROS was chosen as the basis for this OpenType font.
Adobe NotDef maps 1,111,998 Unicode code points to 2,048 .notdef glyphs (CIDs 1 through 2048). The 2,048 High and Low Surrogates (U+D800 through U+DFFF), the two noncharacters in the BMP and in each of the 16 Supplementary Planes (FFFE and FFFF), and the 32 noncharacters in the range U+FDD0 through U+FDEF are explicitly and intentionally excluded. As a fully-functional OpenType font, the following 10 'sfnt' tables are included: CFF, DSIG, OS/2, cmap, head, hhea, hmtx, maxp, name, and post.
In addition to a functional OpenType/CFF font, a TrueType (TTF) version is also included.
To build the binary font files from source, you need to have installed the Adobe Font Development Kit for OpenType (AFDKO). The AFDKO tools are widely used for font development today, and are part of most font editor applications.
In this repository, all necessary files are in place for building the CID-keyed OpenType/CFF and TrueType fonts, and the build.sh file can simply be executed.
For any suggestions for changes, please create a new issue for consideration.