ISO 6937 is a variable-length character encoding as well as an ISO standard, which was first published in 1983. It covers most of the European languages from Latin scripts. The standard was last updated in 2009. ISO 6937 was used by Teletex. To extend the € character ( at position 0xA4 ), ISO 6937 is one of the possible text encodings for DVB.
ISO 6937 encodes the number of accented characters with two bytes where the first byte is the diacritical mark and the second byte of the character to which the diacritic is to be positioned. The possible combinations are just that set, ie not arbitrary.
The following table shows the repertoire of ISO 6937 dar. Blue boxes represent diacritics, green fields unassigned code points. The first 128 characters are identical to ASCII.
Allowable character combinations: