[mkgmap-dev] Minimum size for a "_link" to process "destination"

Hi mkgmap developers, I noticed that when a "_link" containing the tag "destination" (trunk_link, for example) is too small, mkgmap doesn't preprocesse the exit (set dest_hint). For example, if this "_link" has only 8 meters size, no destination nor exit hint is generated by mkgmap for this specific "_link". Could you tell me the "_exit" minimum lenght considered by mkgmap to process destination hint? Thanks. Best regards, Alexandre Loss