Possible Clues:

• LETTERS LIKE THESE
• Big letters, for short (and what your answers must be written in to understand the theme)
• Toppers with visors
• Bold alternative?
• Baseball headgear
• Uppercase letters
• When they're locked, you look like you're shouting
• Toothpaste-tube tops
• Supply for play pistols
• Toothpaste-tube closers