Vocabulary

Capital and capital. There two words are homonyms.

capital - Capital city, the area of a country, province, region, or state, regarded as enjoying primary status, usually but not always the seat of the government
ex, The capital of Russia is Moscow

capital - In economics, capital goods, or real capital are those already-produced durable goods that are used in production of goods or services.
Ex, All the attempts to build capitalism in the USSR failed.

There is also a phrase CAPITAL LETTER:
Capital letter, an upper-case letter in a writing system

Abbreviations:

R.S.V.P. - Répondez s'il vous plaît, or please reply (used at the end of invitations to request a response).
qty - quantity.
thx - thanks
E.T.A. - "Estimated Time of Arrival" or "Edited to Add"
pls cfm - please confirm
@ - at

Here are 40 abbreviations: check your knowledge 

http://www.better-english.com/vocabulary/abbreviations.htm

Advertising vocabulary

http://www.englishclub.com/business-english/vocabulary_advertising.htm

Banking vocabulary

http://www.englishclub.com/business-english/vocabulary_banking.htm

Other:

http://www.englishclub.com/business-english/vocabulary.htm