You are unable to select entities with an underscore or space in its name

You are unable to select mobs (with all @ selectors) that have an underscore or space in the name, this is a big issue because as someone who works with command blocks it makes it very difficult to easily select entities with underscores or spaces in their name, target selectors should be able to recognize underscores or spaces in the names of entities being targeted to be consistent with the name change of most entities.