This dictionary's main concern is current-day slang, chiefly British and then American. Many of the definitions tell when a phrase came into being and also when it ceased being popular as, say, a phrase that was last used in the 1950s. Not many slang dictionaries tell when a phrase fell out of popularity, yet this is a valuable piece of information. In many cases the British use of a slang is compared to the American use: again, a valuable distinction. While I prefer using the slang dictionaries that concentrate on American slang, I wouldn't be without this one: slang jumps from one continent to another with wild abandon, so it's good to know the differences in meaning between one culture's use of a slang phrase and another culture's use of that same phrase.