The receipt number is the serial number of the received document, numbered from 1 downwards, and is used for internal statistics; the document number is the document number printed on the document by the sending unit, and is used for reply or inquiry. (If it is not printed, you can leave it blank).
Of these two numbers, one is for this unit and the other is for external units. As a rule, numbers are numbered from No. 1 downwards each year, with no breaks or duplication of numbers in between, just the same operation.
The sending register generally only registers sending messages, not receiving messages. Since you are only asking about how to fill in the registration book, then you can just fill in the registration items one by one.
The "organizer" can be understood as the unit responsible for issuing this document. Some jointly issue documents, but there can only be one document number. There will be one main unit responsible for it, and other units will cooperate.
If it is a government unit, then the registration book with "sponsoring unit" may not be standardized.
Usually, the contents of the registration of receiving documents include the time of submission, the sending unit, the document name, the document number, the number of copies, the serial number and other filling items.
Extended information:
Receipt and distribution of official documents
(1) Sign for receipt. Refers to the external sending and receiving personnel and communication personnel set up by the agency to receive official documents from the issuing agency, postal department, confidential communication department, document exchange station, or through self-prepared communication equipment after performing the prescribed confirmation, inventory, verification, inspection, and endorsement procedures.
(2) Registration of external receipts. That is, the outsourcing personnel will make a brief record of the receipt of the document after completing the receipt work.
(3) Unsealing. That is, after the registration of external receipts is completed, the official documents are sent to the internal receipt and receipt departments (or personnel) set up by the agency or separately according to the internal organization. After being signed by them, they are uniformly unsealed or sent directly to the relevant leaders for opening.
(4) Registration of included documents. That is, the internal receiving and dispatching personnel will make more detailed records of the receipt of documents.
(5) Branch office. That is, after classifying and screening the received documents, designated relevant personnel will distribute the official documents to relevant leaders and staff of relevant departments for review and processing based on the importance of the official document, division of responsibilities of each department, and relevant procedures.
(6) Excerpt. The processing activities carried out by document management personnel on some important documents that are to be put into the processing process are mainly to write abstracts, summaries, and reviews of these documents, and to collect relevant data and information.
Baidu Encyclopedia-China Collection Processing