Issue:
You are creating a template that includes something like:
IF JOB ABORTS PLEASE EMAIL MY.NAME@MYCOMPANY.COM
In the upper right hand corner of the screen you get a message: ATTRIBUTE NOT ALLOWED
The '@' character in APCDOC is a Template Attribute Character that defines a field as: Required Character Input with Cap. The field being defined is a required input field and all characters entered in the field will be converted to upper case.
Remove the '@'.
You may have a message such as: PLEASE EMAIL MY.NAME AT MYCOMPANY.COM or similar.