The image above is a drop-line head of two parts that says | POST OFFICE ROBBED | BY BAND OF TRAMPS |.
This head would be less effective with the active verb, since the robbery of the post office would then go into the second part of the deck, thus:
The image above is a drop-line head of two parts that says | BAND OF TRAMPS ROB | POST OFFICE SAFE |.
News value rather than rules must determine in any case whether the active or passive voice is desirable.
The use of abbreviations, likewise, cannot be fixed by rule. In general, only commonly used abbreviations, like “Dr.,” “Prof.,” “Mrs.,” “Mr.,” “St.,” “Co.,” are to be found in headlines. In particular cases, however, others are employed because they are convenient and clear. In Boston, for example, “Tech” as an abbreviation for “Massachusetts Institute of Technology,” is common, and the Boston Herald, therefore, used it to advantage in the head:
The image above is of a single drop-line head that says | 200 TECH MEN SEE YULE LOG BLAZE |.
During a long campaign for “immediate municipal ownership” in Chicago, the newspapers of that city used almost daily the abbreviation “I.M.O.” So “L” for “elevated railroad” is perfectly clear to readers in New York, Boston, and Chicago. The names of states are not usually abbreviated, although “U.S.” is frequent. Abbreviations like “auto,” “taxi,” and “phone” are so general that they are used without question in headlines.
Colloquial contractions like “can’t,” “we’re,” etc., although not common, may give the life and naturalness often well suited to a story, as for example in the following head: