RFC-600
- RFC 601 - Traffic statistics (November 1973)
- RFC 602 - "The stockings were hung by the chimney with care"
- RFC 603 - Response to RFC 597: Host status
- RFC 604 - Assigned link numbers
- RFC 606 - Host names on-line
- RFC 607 - Comments on the File Transfer Protocol
- RFC 608 - Host names on-line
- RFC 609 - Statement of upcoming move of NIC/NLS service
- RFC 610 - Further datalanguage design concepts
- RFC 611 - Two changes to the IMP/Host Protocol to improve user/network communications
- RFC 612 - Traffic statistics (December 1973)
- RFC 613 - Network connectivity: A response to RFC 603
- RFC 614 - Response to RFC 607: "Comments on the File Transfer Protocol"
- RFC 615 - Proposed Network Standard Data Pathname syntax
- RFC 616 - LATEST NETWORK MAPS
- RFC 617 - Note on socket number assignment
- RFC 618 - Few observations on NCP statistics
- RFC 619 - Mean round-trip times in the ARPANET
- RFC 620 - Request for monitor host table updates
- RFC 621 - NIC user directories at SRI ARC
- RFC 622 - Scheduling IMP/TIP down time
- RFC 623 - Comments on on-line host name service
- RFC 624 - Comments on the File Transfer Protocol
- RFC 625 - On-line hostnames service
- RFC 626 - On a possible lockup condition in IMP subnet due to message sequencing
- RFC 627 - ASCII text file of hostnames
- RFC 628 - Status of RFC numbers and a note on pre-assigned journal numbers
- RFC 629 - Scenario for using the Network Journal
- RFC 630 - FTP error code usage for more reliable mail service
- RFC 631 - International meeting on minicomputers and data communication: Call for papers
- RFC 632 - Throughput degradations for single packet messages
- RFC 633 - IMP/TIP preventive maintenance schedule
- RFC 634 - Change in network address for Haskins Lab
- RFC 635 - Assessment of ARPANET protocols
- RFC 636 - TIP/Tenex reliability improvements
- RFC 637 - Change of network address for SU-DSL
- RFC 638 - IMP/TIP preventive maintenance schedule
- RFC 640 - Revised FTP reply codes
- RFC 642 - Ready line philosophy and implementation
- RFC 643 - Network Debugging Protocol
- RFC 644 - On the problem of signature authentication for network mail
- RFC 645 - Network Standard Data Specification syntax
- RFC 647 - Proposed protocol for connecting host computers to ARPA-like networks via front end processors
- RFC 651 - Revised Telnet status option
- RFC 652 - Telnet output carriage-return disposition option
- RFC 653 - Telnet output horizontal tabstops option
- RFC 654 - Telnet output horizontal tab disposition option
- RFC 655 - Telnet output formfeed disposition option
- RFC 656 - Telnet output vertical tabstops option
- RFC 657 - Telnet output vertical tab disposition option
- RFC 658 - Telnet output linefeed disposition
- RFC 659 - Announcing additional Telnet options
- RFC 660 - Some changes to the IMP and the IMP/Host interface
- RFC 661 - Protocol information
- RFC 662 - Performance improvement in ARPANET file transfers from Multics
- RFC 663 - Lost message detection and recovery protocol
- RFC 666 - Specification of the Unified User-Level Protocol
- RFC 667 - Host Ports
- RFC 669 - November, 1974, survey of New-Protocol Telnet servers
- RFC 671 - Note on Reconnection Protocol
- RFC 672 - Multi-site data collection facility
- RFC 674 - Procedure call documents: Version 2
- RFC 675 - Specification of Internet Transmission Control Program
- RFC 677 - Maintenance of duplicate databases
- RFC 678 - Standard file formats
- RFC 679 - February, 1975, survey of New-Protocol Telnet servers
- RFC 680 - Message Transmission Protocol
- RFC 681 - Network UNIX
- RFC 683 - FTPSRV - Tenex extension for paged files
- RFC 684 - Commentary on procedure calling as a network protocol
- RFC 685 - Response time in cross network debugging
- RFC 686 - Leaving well enough alone
- RFC 687 - IMP/Host and Host/IMP Protocol changes
- RFC 688 - Tentative schedule for the new Telnet implementation for the TIP
- RFC 689 - Tenex NCP finite state machine for connections
- RFC 690 - Comments on the proposed Host/IMP Protocol changes
- RFC 691 - One more try on the FTP
- RFC 692 - Comments on IMP/Host Protocol changes (RFCs 687 and 690)
- RFC 694 - Protocol information
- RFC 695 - Official change in Host-Host Protocol
- RFC 696 - Comments on the IMP/Host and Host/IMP Protocol changes
- RFC 697 - CWD command of FTP
- RFC 698 - Telnet extended ASCII option
- RFC 699 - Request For Comments summary notes: 600-699
- RFC 700 - Protocol experiment