international telegraph alphabet (ITA)
The International Telegraph Alphabets (ITA) are character sets standardized by the International Telecommunication Union(ITU) with letters, digits, characters and special characters for the transmission of texts in public networks.
There are two different telegraph alphabets, the IA-2 alphabet and the IA-5 alphabet. In addition to the IA-2 and IA-5 designations, one also finds the designation ITC2 for International Telegraph Code No. 2. The IA-2 alphabet is a 5-bit code with 32 characters that was used in classic teletype technology.
The IA-5 alphabet (International Alphabet 5) is a 7-bit code with 128 characters.