Matches the capitalization of how the snippet shortcut was typed. If the shortcut is typed in all caps, the text will be converted to all caps. If the shortcut is typed in all lowercase, the text will be converted to all lowercase. And if the shortcut is typed in a mixture of upper and lowercase, the text will be inserted in the original capitalization.
The text to match the case. You should type this in the capitalization you want to use when the shortcut is mixed-case.
For example, we have a snippet with the shortcut "/ty" and the contents: "Thank you!":
typing "/ty" will insert "thank you!"
typing "/TY" will insert "THANK YOU!"
typing "/Ty" will insert "Thank you!" (the original capitalization)