Hi Ticker, I guess variables like mkgmap:us_interstate come from my style. I use them for shields with road reference numbers. There are dedicated shields for US maps and standard shields for other countries. These variables allows to create single style for both cases. This is an example from my style, file "lines": # Set highway names to include the reference if there is one highway=motorway & mkgmap:us_interstate=* {name '${mkgmap:us_interstate|highway-symbol:interstate:12}'; addlabel '${name|not-equal:ref}'; set mkgmap:refnam=yes} highway=motorway & mkgmap:refnam!=* & mkgmap:us_usroute=* {name '${mkgmap:us_usroute|highway-symbol:shield:12}'; addlabel '${name|not-equal:ref}'; set mkgmap:refnam=yes} highway=motorway & mkgmap:refnam!=* & mkgmap:us_state=* {name '${mkgmap:us_state|highway-symbol:round:12}'; addlabel '${name|not-equal:ref}'; set mkgmap:refnam=yes} highway=motorway & mkgmap:refnam!=* & mkgmap:admin_level2=USA {name '${name}' | '${ref}'; set mkgmap:refnam=yes} #disable box highway=motorway & mkgmap:refnam!=* & mkgmap:admin_level2!=USA {name '${ref|highway-symbol:hbox:12}'; addlabel '${name|not-equal:ref}'; set mkgmap:refnam=yes} highway=trunk & mkgmap:refnam!=* & mkgmap:admin_level2!=USA {name '${ref|highway-symbol:hbox:12}'; addlabel '${name|not-equal:ref}'; set mkgmap:refnam=yes} highway=* & mkgmap:refnam!=* & mkgmap:us_interstate=* {name '${mkgmap:us_interstate|highway-symbol:interstate:12}'; addlabel '${name|not-equal:ref}'; set mkgmap:refnam=yes} highway=* & mkgmap:refnam!=* & mkgmap:us_usroute=* {name '${mkgmap:us_usroute|highway-symbol:shield:12}'; addlabel '${name|not-equal:ref}'; set mkgmap:refnam=yes} highway=* & mkgmap:refnam!=* & mkgmap:us_state=* {name '${mkgmap:us_state|highway-symbol:round:12}'; addlabel '${name|not-equal:ref}'; set mkgmap:refnam=yes} highway=* & mkgmap:refnam!=* & mkgmap:admin_level2=USA {name '${name}' | '${ref}'; set mkgmap:refnam=yes} #disable box highway=primary & mkgmap:refnam!=* & (name=* | ref=*) {name '${name|not-equal:ref}' | '${ref|highway-symbol:box:12}'; set mkgmap:refnam=yes} highway=secondary & mkgmap:refnam!=* & (name=* | ref=*) {name '${name|not-equal:ref}' | '${ref|highway-symbol:oval:12}'; set mkgmap:refnam=yes} highway=* & mkgmap:refnam!=* {name '${name}' | '${ref}'} -- Best regards, Andrzej