PSYC has a template syntax by the MIME type text/x-psyc also known as psyctext. It allows for errors, warnings and other automatically generated messages to be both readable for humans and automatons. The variable names in brackets SHOULD be replaced by the actual content of the variable, when presented to the user.

     Example:
     	:_method        i
       _error_unsupported_method
       No such method '[_method]' defined here.
       |

This should display as

       No such method 'i' defined here.

When no match is found, like in the case of a template containing array[i++] where a variable called i++ does not exist, the string remains unchanged. This is not an error.