For example, if I create an SVG and use an externally referenced font file, and if that font files has 100 glyphs, but my SVG only uses 10 of the glyphs, do the 90 unused glyphs gets stripped out of the font file before Base64 encoding? This is essentially my work flow with some other tools, doing the steps manually. Results are good but the process is tedious. Looking for a pure C program to portably compile on Android (Termux, Clang, NDK, BIONIC), Windows, and Linux, install as a Node.js package, and automate the process. I may have to write it myself and release as open source.