Within BIMcollab Twin, the document number is incredibly important. This is because the entire version management depends on corresponding document numbers. When uploading documents, it is checked whether the document number is already known within the corresponding project. If so, the new document is linked as a newer version of the same document.
For the clarity of the documents it is also advised to have a fixed way in which documents are numbered. You should be able to deduce the document's topic from the number itself. Unambiguous numbering of documents is therefore not only important for BIMcollab Twin but also for yourself, your project team and all users of the information who will work with it after you.