CCITT Rec. F.72 (11/1988) – INTERNATIONAL TELEX STORE AND FORWARD – GENERAL PRINCIPLES AND OPERATIONAL ASPECTS
1 Scope
2 General
3 Service requirements
    3.1 Message identification
    3.2 Service codes
    3.3 Duration of message storage
    3.4 Maximum message length and duration
    3.5 Store full indication
    3.6 End of transaction and end of message signal
    3.7 Input transaction accepted
    3.8 Message security
    3.9 Advice of non-delivery/delivery
    3.10 Message status enquiry point
    3.11 Call records
    3.12 Incomplete message
4 Facilities
    4.1 Single address
    4.2 Multi-address
    4.3 Follow-on messages
    4.4 Classes of delivery
    4.5 Cancellation
    4.6 Address correction
5 Quality of service
    5.1 Loss probability in the store and forward procedure
    5.2 Error protection
    5.3 Duration of service
    5.4 Number of circuits
    5.5 Minimum storage capacity
6 Access principles
7 Access procedures
    7.1 General
    7.2 Telex access
    7.3 Service request
    7.4 Message input
8 Information field content for address line
    8.1 Message input address line
9 SFU access protocol
    9.1 Note 1
    9.2 Note 2
    9.3 Note 3 – Case A
    9.4 Note 4 – Case B
    9.5 Note 5
    9.6 Note 6
    9.7 Note 7
    9.8 Note 8
    9.9 Note 9
    9.10 Note 10
    9.11 Note 11
    9.12 Note 12
    9.13 Note 13
10 Abnormal conditions during message input
    10.1 Telex subscriber clearing during text input without EOT
    10.2 Telex subscriber stopping transmission for a certain time without transmitting the EOT signal, or transmitting a partial, or invalid EOT signal
    10.3 Telex subscriber sending WRU to SFU during text input
    10.4 Telex subscriber sending text after the EOT signal
    10.5 Telex subscriber clearing after EOT but before ITD
    10.6 Telex subscriber sending national variants of ITA No. 2 alphabet – (↑F, ↑G, ↑H)
    10.7 Telex subscriber sending J Bell combination (↑J) 
    10.8 SFU storage capacity overflow during telex message input
    10.9 Repeated characters during message input
11 Status enquiry
12 Delivery procedure
13 Notification procedures
    13.1 Types of notification
    13.2 Notification delivery procedures
14 Delivery retry procedures
15 Field content delivery/non-delivery notification
16 Special provisions for interconnected telex store and forward
    16.1 Service outline
    16.2 International interconnection
    16.3 Elements of inter-SFU message transfer procedure