It is probably the HIN (Hull Identification Number)
If you know the code (I do not) then it shows country of manufacture, who the builder was, year and hull build within that year ( I don’t know whether this is all boats built or just Wayfarers) it does not relate directly to the Sail number.
I think its to do with EU compliance regulations.
GBOVM30705D404 relates to a Mumm30 Built by Ovington Marine in 2004
GBRCH014B212 relates to a 2012 Wayfarer