2: Never use full stops with Degrees, Qualifications, Titles, and Awards as it is increasingly famous in British English. e.g. MBA, BBA, BSc, MA, MSc, M Phil etc 3: We never use full stops with abbreviations of ordinal numbers. e.g. 1st September, 2nd October, 3rd November, 4th December Note: But date, in fact, is very often simply written 1 September, 2 October, 3 November and 4 December, and so on, especially in formal context. 4: We do not use full stops abbreviations of Metric Measurement and Chemical Symbols. e.g. 21 cm, 6 km, 10 g, 5 kg, 20 dl, 30 ml Metric Measurement/ Chemical Symbols Al (aluminum), Ca (calcium), Mg (magnesium), O (oxygen), Ra (radium) 24