Comment 4 for bug 387848

in conf.d README, the following is said about the priorities:

Files begining with: Contain:

 00 through 09 Font directories
 10 through 19 system rendering defaults (AA, etc)
 20 through 29 font rendering options
 30 through 39 family substitution
 40 through 49 generic identification, map family->generic
 50 through 59 alternate config file loading
 60 through 69 generic aliases, map generic->family
 70 through 79 select font (adjust which fonts are available)
 80 through 89 match target="scan" (modify scanned patterns)
 90 through 99 font synthesis

Isnt that scheme used properly for *-latin.conf ?