Postal, telegraph and telephone service

In countries that had a PTT unit of government, typically the vast majority of forms of distribution of information fell under the auspices of the PTT, whether that be the delivery of printed publications and individual letters in the postal mail, the transmission of telephonic audio, or the transmission of telegraphic on-off signals, and in some countries, the broadcast of one-way (audio) radio and (audio-video) television signals. In many countries with a current or former PTT, the PTT was also responsible for the manufacture and standardisation of telephone equipment. Often the presence of a single PTT in a country implied a single monolithic approach to the distribution of information in that country, which as an advantage permitted efficient deployment of a single national standard for each topic instead of ongoing debate about competing ideas, but which as a disadvantage typically stifled alternative ideas from emerging once a legacy implementation had been widely deployed.