Thread:Extension talk:Poem/The =-sign within a text that's part of a poem embedded in a template./reply (2)

This is because when you write the parser thinks you wish to invoke quote with a single parameter named "". If you have a named parameter, it does not get assigned a number: that's only for anonymous parameters. So does not have a value, and you have not used a pipe to indicate a default value, so you get the raw parameter showing up as above.