RFC-500
- RFC 501 - Un-muddling "free file transfer"
- RFC 503 - Socket number list
- RFC 504 - Distributed resources workshop announcement
- RFC 505 - Two solutions to a file transfer access problem
- RFC 506 - FTP command naming problem
- RFC 508 - Real-time data transmission on the ARPANET
- RFC 509 - Traffic statistics (April 1973)
- RFC 510 - Request for network mailbox addresses
- RFC 511 - Enterprise phone service to NIC from ARPANET sites
- RFC 512 - More on lost message detection
- RFC 513 - Comments on the new Telnet specifications
- RFC 514 - Network make-work
- RFC 515 - Specifications for Datalanguage, Version 0/9
- RFC 516 - Lost message detection
- RFC 518 - ARPANET accounts
- RFC 519 - Resource Evaluation
- RFC 520 - Memo to FTP group: Proposal for File Access Protocol
- RFC 521 - Restricted use of IMP DDT
- RFC 522 - Traffic Statistics (May 1973)
- RFC 523 - SURVEY is in operation again
- RFC 524 - Proposed Mail Protocol
- RFC 525 - MIT-MATHLAB meets UCSB-OLS -an example of resource sharing
- RFC 526 - Technical meeting: Digital image processing software systems
- RFC 527 - ARPAWOCKY
- RFC 528 - Software checksumming in the IMP and network reliability
- RFC 529 - Note on protocol synch sequences
- RFC 531 - Feast or famine? A response to two recent RFC's about network information
- RFC 532 - UCSD-CC Server-FTP facility
- RFC 533 - Message-ID numbers
- RFC 534 - Lost message detection
- RFC 535 - Comments on File Access Protocol
- RFC 537 - Announcement of NGG meeting July 16-17
- RFC 538 - Traffic statistics (June 1973)
- RFC 539 - Thoughts on the mail protocol proposed in RFC 524
- RFC 542 - File Transfer Protocol
- RFC 543 - Network journal submission and delivery
- RFC 544 - Locating on-line documentation at SRI-ARC
- RFC 545 - Of what quality be the UCSB resources evaluators?
- RFC 546 - Tenex load averages for July 1973
- RFC 547 - Change to the Very Distant Host specification
- RFC 548 - Hosts using the IMP Going Down message
- RFC 549 - Minutes of Network Graphics Group meeting, 15-17 July 1973
- RFC 550 - NIC NCP experiment
- RFC 551 - NYU, ANL, and LBL Joining the Net
- RFC 552 - Single access to standard protocols
- RFC 553 - Draft design for a text/graphics protocol
- RFC 555 - Responses to critiques of the proposed mail protocol
- RFC 556 - Traffic Statistics (July 1973)
- RFC 557 - REVELATIONS IN NETWORK HOST MEASUREMENTS
- RFC 559 - Comments on The New Telnet Protocol and its Implementation
- RFC 560 - Remote Controlled Transmission and Echoing Telnet option
- RFC 561 - Standardizing Network Mail Headers
- RFC 562 - Modifications to the TELNET Specification
- RFC 563 - Comments on the RCTE Telnet option
- RFC 565 - Storing network survey data at the datacomputer
- RFC 566 - Traffic statistics (August 1973)
- RFC 567 - Cross Country Network Bandwidth
- RFC 568 - Response to RFC 567 - cross country network bandwidth
- RFC 569 - NETED: A Common Editor for the ARPA Network
- RFC 570 - Experimental input mapping between NVT ASCII and UCSB On Line System
- RFC 571 - TENEX FTP PROBLEM
- RFC 573 - DATA AND FILE TRANSFER - SOME MEASUREMENT RESULTS
- RFC 574 - Announcement of a Mail Facility at UCSB
- RFC 576 - Proposal for modifying linking
- RFC 577 - Mail priority
- RFC 578 - Using MIT-Mathlab MACSYMA from MIT-DMS Muddle
- RFC 579 - Traffic statistics (September 1973)
- RFC 580 - Note to Protocol Designers and Implementers
- RFC 581 - Corrections to RFC 560: Remote Controlled Transmission and Echoing Telnet Option
- RFC 582 - Comments on RFC 580: Machine readable protocols
- RFC 584 - Charter for ARPANET Users Interest Working Group
- RFC 585 - ARPANET users interest working group meeting
- RFC 586 - Traffic statistics (October 1973)
- RFC 587 - Announcing New Telnet Options
- RFC 588 - London Node Is Now Up
- RFC 589 - CCN NETRJS server messages to remote user
- RFC 590 - MULTICS address change
- RFC 591 - Addition to the Very Distant Host specifications
- RFC 592 - Some thoughts on system design to facilitate resource sharing
- RFC 593 - Telnet and FTP implementation schedule change
- RFC 594 - Speedup of Host-IMP interface
- RFC 595 - Second thoughts in defense of the Telnet Go-Ahead
- RFC 596 - Second thoughts on Telnet Go-Ahead
- RFC 597 - Host status
- RFC 599 - Update on NETRJS
- RFC 600 - Interfacing an Illinois plasma terminal to the ARPANET