For some reason, unlike in Wales which has a much better track record with maps, maps of Scotland tend to still show anglicised forms on the mainland whose mangling makes placenames hard to decipher. Some maps are doing rather better in the Western Isles but have yet to get their act together on the mainland and in Skye. Many many obvious mistakes, misspellings and grammatical errors abound which would not be found in Wales and no maps of England would dare exhibit misspellings such as ‘*Burminghum’. Recently the authorities aided by the Scottish Placename Society, of which I am a member, and other bodies have done a good job getting all the road signs fixed but trying to sort out all the various maps is a Herculean task.
In many parts of the country the placenames are Norse (Old Norwegian) mangled by Gaelic speakers or from British (ie Welsh), not Gaelic and some have been ‘gaelicised’ in spelling. For these names it seems anything goes but now the tendency is to increasingly spell these names with phonetic Gaelic spelling based on the pronunciation of local Gaelic speakers, which is a sensible choice.
English speaking readers have to cope with the complex coding system which Scottish Gaelic and Irish use to encode far too many consonants into the few symbols provided by the Latin alphabet. Welsh does not have this problem because it has only approximately half as many consonants. The letter h after a consonant can be present or absent and one of two sets of extra vowels are used to bracket consonants - the sets are a/o/u and e/i, one or the other - and this choice between the two sets, combined with the +/- h option gives four possible consonant sounds per core consonant letter. To prevent ambiguity the vowels on either side of any consonant must be from the same set.
Vowels can be short or long and in traditional Gaelic spelling there can be à ì ù and è ò | é ó, the accents are used to mark long vowels and the choice of grave vs acute for e or o gives different sounds. So the number is sounds is massive, Gaelic spelling is a code, and like utf-8 it needs decoding first; in the code, multiple letters convert into single sounds. Compare English mac and mace where the addition of the silent e changes the consonant and the vowel. The difficulty for an English-speaking audience perhaps explains some of the differences in historical map-making practice between Wales and Scotland.
