Converts the first ASCII letter character of a string to uppercase. This behavior is different from the magic word ucfirst, which affects the first character of a string regardless of whether it is a letter or not.

{{ucfirstletter|test}} → Test

{{ucfirstletter|(test)}} → (Test)

{{ucfirstletter|6th century}} → 6Th century

(compare to {{ucfirst:6th century}} → 6th century)