The official definition of the ISO Latin 1 character repertoire in the ISO 8859-1 standard "does not define and does not restrict the meanings of graphic characters", except for the following characters: space, no-break space, soft hyphen. It says that "the names chosen to denote graphic characters are intended to reflect their customary meaning", but as far as the ISO 8859-1 standard is concerned, you might use most of the characters for whatever you like. The price to pay for this "liberalism" is that you cannot assume that other people and computer programs will interpret the characters the same way as you.
On the other hand, the Unicode standard contains quite detailed notes on the use of characters. Some of the notes related to characters in the ISO Latin 1 repertoire are available, in PDF format, online as parts Basic Latin and Latin-1 Supplement of Unicode charts. It seems reasonable to use ISO Latin 1 characters according to the semantics specified in the Unicode standard.