The BS 7666 is just a rationalization. There is a definition of CharacterString to be alphanumeric, which would be silly to use strictly since that would also f

The BS 7666 is just a rationalization. There is a definition of CharacterString to be alphanumeric, which would be silly to use strictly since that would also forbid white space and hyphens. Later in the spec there is a specific example containing an apostrophe. "Abbreviations and punctuation should not be used unless they appear in the designated name (e.g. ‘Earl’s Court Road’). Only single spaces should be used, and the use of leading spaces should be avoided." So some system the council deals with can't cope, and they are trying to rationalize not fixing it.