Because of space constraints, a copy editing requirement is the ability to write headlines in a compressed telegraphic style. Headlines often omit forms of the verb "to be" and other grammatical articles, or use verbs' infinitives for the future tense, as in "Dow Jones board to vote on News Corp offer". Virtually no finite verbs are used except in the simple present tense.
Conjunctions are also often excluded from headlines. In the United States, for example, the word "and" is often replaced by a comma, as in "Bush, Blair laugh off microphone mishap".
Headlines feature many contractions and abbreviations: in the USA, for example, Pols (for "politicians"), Dems (for "Democrats"), GOP (for the Republican Party, from the nickname "Grand Old Party"); in the UK, Lib Dems (for the Liberal Democrats), Tories (for the Conservative Party). Some periodicals have their own distinctive headline styles, especially Variety and its entertainment-jargon headlines such as "Sticks nix hick pix".
The vocabulary and grammatical constructs used in headlines have become so culturally ingrained that they are often encountered even where there are no space constraints, for example in internet news agencies' headlines.