This is a defense against a weak two preempt in a major. A jump
shows a game-going hand with 5-5 in the suit and the other major.
2H 4C shows clubs and spades
2S 4D shows diamonds and hearts
Other partnerships may play a Roman Jump shows 5-5 in the suit bid and the suit above it. (Thus 4C over 2H would show clubs and diamonds).
(My idea:) You could incorporate Roman Jumps and a direct cue bid to show all 5-5 hands:
Over weak 2(major): jump = suit + other major
cue = both minors
Over weak 2(minor): jump = suit + other minor
cue = both majors