Is It Right To Use Abbreviations in Formal Writing? If Yes, What Type?

According to an article on about.com, an abbreviation is a shortened form of a word or phrase, such as Jan for January; Dr for Doctor; Mrs for Missus etc. The abbreviated form of the word abbreviation is abbr. or, less commonly, abbrv. or abbrev. In British English, which we favour, the usage of abbreviations generally favours omitting the period (or full stop) in [...]