The package provides commands \makefirstuc that uppercases the first letter in its argument (with a check for a semantic markup command at the start of the argument), and \xmakefirstuc which expands the argument before uppercasing. It also provides \capitalisewords{phrase} which applies \makefirstuc to each word in the phrase, where the words are separated by regular spaces. (Exceptions can be made for words that shouldn't be converted.)