They have different meanings. The difference between text and signature is that they have different meanings. Signature refers to the definition of descriptor table (including its layout), root constant and any set of root descriptors. The cost of each entry is close to the maximum limit, so the application can weigh the number of each type of entry that the signature will contain. Orthodoxy is to write one's name on official documents on formal occasions, especially in order to express agreement, recognition, responsibility or obligation.