The product identification record has tag code 1. It consists of a single string field giving the name of the product that wrote the portable file.
The author identification record has tag code 2. It is optional. If present, it consists of a single string field giving the name of the person who caused the portable file to be written.
The subproduct identification record has tag code 3. It is optional. If present, it consists of a single string field giving additional information on the product that wrote the portable file.