The present disclosure relates to magenta inkjet inks having a quinacridone pigment and an azo pigment. The azo pigment has at least one azo compound having the formula (I), in which R.sub.a is selected from H, aryl and C.sub.1 to C.sub.4 alkyl, and R.sub.b, R.sub.c and R.sub.d are each independently selected from H, a C.sub.1 to C.sub.4 alkyl, an oxygen-containing, a nitrogen-containing and a sulphur-containing functional group. Where R.sub.a is aryl, the aryl is not a phenyl group having at least one hydrogen atom that has been substituted with a chlorine atom. ##STR00001##

Embodiments of the present invention provide a computer-implemented method for assigning identifiers to geographic locations within digital map data, comprising selecting a region within the map data, dividing the region into a first plurality of cells each uniquely addressable by an identifier of a first length, selecting a portion of the region and dividing the portion into a second plurality of cells each uniquely addressable by an identifier of a second length, wherein the second length is shorter length than the first length and a geographic location within the portion of the region may be uniquely identified by an identifier of the first length and an identifier of the second length.

The present disclosure relates to magenta inkjet inks having a quinacridone pigment and an azo pigment. The azo pigment has at least one azo compound having the formula (I), in which R.sub.a is selected from H, aryl and C.sub.1 to C.sub.4 alkyl, and R.sub.b, R.sub.c and R.sub.d are each independently selected from H, a C.sub.1 to C.sub.4 alkyl, an oxygen-containing, a nitrogen-containing and a sulphur-containing functional group. Where R.sub.a is aryl, the aryl is not a phenyl group having at least one hydrogen atom that has been substituted with a chlorine atom.

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