Hyphen-smashing refers to the ability to use any character's Usmash during a dash. Depending on the character, this could greatly increase the ability to land their Usmashes and give them an Usmash with slightly more range.
A hyphen smash can also be used as an alternative to boost smashing. If your character's boost smash does not have great range, sometimes the better option is to go with a hyphen smash. The best thing to do with a hyphen smash is to get a good dash in so that it increases your momentum, the more momentum in your dash, the more deadly the hyphen smash will be. This method has been tested by using two CPU's in training mode. One CPU was hit by a hyphen smash with little momentum, while the other CPU was hit with full momentum. The CPU hit with full momentum in the hyphen smash had a slightly greater knockback. However, damage dealt from the hyphen smashes were the same.