"WARNING: FFTM NOT subset; don't know how to subset; dropped"

[sadokx]

I am getting this warning, not sure what it means. Fonts are Gudea and Rajdhani, both from Google Fonts. Thanks for the help!

[zachleat]

See the output from pyftsubset --help here:

Font table options:
  --drop-tables[+|-]=<table>[,<table>...]
      Specify (=), add to (+=) or exclude from (-=) the comma-separated
      set of tables that will be be dropped.
      By default, the following tables are dropped:
      'BASE', 'JSTF', 'DSIG', 'EBDT', 'EBLC', 'EBSC', 'SVG ', 'PCLT', 'LTSH'
      and Graphite tables: 'Feat', 'Glat', 'Gloc', 'Silf', 'Sill'
      and color tables: 'CBLC', 'CBDT', 'sbix'.
      The tool will attempt to subset the remaining tables.
      Examples:
        --drop-tables-='SVG '
            * Drop the default set of tables but keep 'SVG '.
        --drop-tables+=GSUB
            * Drop the default set of tables and 'GSUB'.
        --drop-tables=DSIG
            * Only drop the 'DSIG' table, keep all others.
        --drop-tables=
            * Keep all tables.
  --no-subset-tables+=<table>[,<table>...]
      Add to the set of tables that will not be subsetted.
      By default, the following tables are included in this list, as
      they do not need subsetting (ignore the fact that 'loca' is listed
      here): 'gasp', 'head', 'hhea', 'maxp', 'vhea', 'OS/2', 'loca',
      'name', 'cvt ', 'fpgm', 'prep', 'VMDX', 'DSIG' and 'CPAL'.
      By default, tables that the tool does not know how to subset and are not
      specified here will be dropped from the font, unless --passthrough-tables
      option is passed.
      Example:
         --no-subset-tables+=FFTM
            * Keep 'FFTM' table in the font by preventing subsetting.
  --passthrough-tables
      Do not drop tables that the tool does not know how to subset.
  --no-passthrough-tables
      Tables that the tool does not know how to subset and are not specified
      in --no-subset-tables will be dropped from the font. [default]

pyftsubset doesn’t know how to subset the FFTM table and it is dropped from the output. This might be bad or it might be okay?

After further research it looks fine, it’s just proprietary fontforge timestamps:

https://fontforge.github.io/TrueOpenTables.html

This table is unique to FontForge. It contains three timestamps: First FontForge's version date, then when the font was generated, and when the font was created. I describe its format here.