SPQR, is a short form for ‘Senātus Populusque Rōmānus’, meaning ‘The Roman Senate and People’ or ‘The Senate and People of Rome’. It is an emblematic phrase referring to the government of the ancient Roman Republic. It appears on Roman currency, at the end of documents made public by an inscription in stone or metal, and in dedications of monuments and public and civil works.

Even in modern usage, SPQR is still used in the municipal coat of arms of Rome and as abbreviation for the community of Rome in official documents. The Italians have long used a different and humorous expansion of this abbreviation: ‘Sono Pazzi Questi Romani’, which means, ‘They're crazy, these Romans’.

In Spain, SPQR is also used in the flag and coat of arms of Sabiñánigo.

In business, in English-speaking countries, SPQR is sometimes (humorously) used to mean ‘Small Profit, Quick Return’, often by people who have studied Latin at school.

More Info: en.wikipedia.org