Adobe text tags in word documents 'Form filler'

I tagged my word documents with adobe sign text tags as example:

{{Ort_es_:signer1:required:string(char=alpha):dimension(width=30mm, height=6mm)}}

Now I want to change the role 'signer1' in 'form filler1', but it doesn't work. With this term everybody can fill in the field.

I didn't find any hint in the tag documentation, which term is correct.

Can anybody help me?