On the last page of my document, I've noticed that the attachments get an extended numerical code starting with "hash 256", but what exactly is it?

The numeric code is a hash value and acts as a digital fingerprint on files and data. The numbered code is unique to each file and is generated using a mathematical algorithm. 

The unique thing about this is that the hash value changes if the file is altered. It is called a cryptographic hash function and is, in a way, the unique identity of the file.

This way, the sender and recipient can agree on the content of the agreements.

Can I contact you with suggestions and requests for improvements and new features?

Yes, we receive user feedback and suggestions with open arms. If you have an idea of how we can make life better for our users, we would love to hear from you at help@signit.eu.