[mkgmap-dev] Why are all the un-named peaks called '6140565'?

Stylists, Just noticed that in the UK map, points tagged natural=peak that don't have a name are showing a name of '6140565'. I guess it's something to do with this rule from the points file: natural=peak {name '${name|def:}${ele|height:m=>ft|def:}' } [0x6616 resolution 18] The style language is completely beyond me, what's it doing? Mark