| List of ITU-T R-Series Recommendations in force | |
| [R.2] Recommendation R.2 (11/88) - Element error rate | 20 CHF |
| [R.4] Recommendation R.4 (11/88) - Methods for the separate measurements of the degrees of various types of telegraph distortion | 20 CHF |
| [R.5] Recommendation R.5 (03/93) - Observation conditions recommended for routine distortion measurements on international telegraph circuits | 20 CHF |
| [R.9] Recommendation R.9 (03/93) - How the laws governing distribution of distortion should be arrived at | 20 CHF |
| [R.11] Recommendation R.11 (03/93) - Calculation of the degree of distortion of a telegraphie circuit in terms of the degrees of distortion of the component links | 20 CHF |
| [R.20] Recommendation R.20 (11/88) - Telegraph modem for subscriber lines | 20 CHF |
| [R.21] Recommendation R.21 (08/96) - 9600 bit/s modem standardized for use in the telegraph TDM system | 20 CHF |
| [R.22] Recommendation R.22 (08/96) - Data over voice 19 200 bit/s modem standardized for use on telephone network subscriber lines | 20 CHF |
| [R.30] Recommendation R.30 (11/88) - Transmission characteristic for international VFT links | 20 CHF |
| [R.31] Recommendation R.31 (11/88) - Standardization of AMVFT systems for a modulation rate of 50 bauds | 20 CHF |
| [R.35] Recommendation R.35 (11/88) - Standardization of FMVFT systems for a modulation rate of 50 bauds | 20 CHF |
| [R.35 bis] Recommendation R.35 bis (11/88) - 50-baud wideband VFT systems | 20 CHF |
| [R.36] Recommendation R.36 (11/88) - Coexistence of 50-baud/120-Hz channels, 100-baud/240-Hz channels, 200-baud/360-Hz or 480-Hz channels on the same voice-frequency telegraph system | 20 CHF |
| [R.37] Recommendation R.37 (11/88) - Standardization of FMVFT systems for a modulation rate of 100 bauds | 20 CHF |
| [R.38 A] Recommendation R.38 A (11/88) - Standardization of FMVFT system for a modulation rate of 200 bauds with channels spaced at 480 Hz | 20 CHF |
| [R.38 B] Recommendation R.38 B (11/88) - Standardization of FMVFT systems for a modulation rate of 200 bauds with channels spaced at 360 Hz usable on long intercontinental bearer circuits generally used with a 3-Hz spacing | 20 CHF |
| [R.39] Recommendation R.39 (11/88) - Voice-frequency telegraphy on radio circuits | 20 CHF |
| [R.40] Recommendation R.40 (11/88) - Coexistence in the same cable of telephony and super-telephone telegraphy | 20 CHF |
| [R.43] Recommendation R.43 (11/88) - Simultaneous communication by telephone and telegraph on a telephone-type circuit | 20 CHF |
| [R.44] Recommendation R.44 (11/88) - 6-unit synchronous time-division 2-3-channel multiplex telegraph system for use over FMVFT channels spaced at 120 Hz for connection to standardized teleprinter networks | 20 CHF |
| [R.49] Recommendation R.49 (11/88) - Interband telegraphy over open-wire 3-channel carrier systems | 20 CHF |
| [R.50] Recommendation R.50 (11/88) - Tolerable limits for the degree of isochronous distortion of code-independent 50-baud telegraph circuits | 20 CHF |
| [R.51] Recommendation R.51 (11/88) - Standardized text for distortion testing of the code-independent elements of a complete circuit | 20 CHF |
| [R.51 bis] Recommendation R.51 bis (11/88) - Standardized text for testing the elements of a complete circuit | 20 CHF |
| [R.52] Recommendation R.52 (11/88) - Standardization of international texts for the measurement of the margin of start-stop equipment | 20 CHF |
| [R.53] Recommendation R.53 (11/88) - Permissible limits for the degree of distortion on an international 50-baud/120-Hz VFT channel (Frequency and amplitude modulation) | 20 CHF |
| [R.54] Recommendation R.54 (03/93) - Conventional degree of distortion tolerable for standardized start-stop 50-baud systems | 20 CHF |
| [R.55] Recommendation R.55 (03/93) - Conventional degree of distortion | 20 CHF |
| [R.56] Recommendation R.56 (03/93) - Telegraph distortion limits to be quoted in Recommendations for equipment and transmission plans | 20 CHF |
| [R.57] Recommendation R.57 (11/88) - Standard limits of transmission quality for planning code-independent international point-to-point telegraph communications and switched networks using 50-baud start-stop equipment | 20 CHF |
| [R.58] Recommendation R.58 (11/88) - Standard limits of transmission quality for the gentex and telex networks | 20 CHF |
| [R58 bis] Recommendation R.58 bis (11/88) - Limits on signal transfer delay for telegraph, telex and gentex networks | 20 CHF |
| [R.59] Recommendation R.59 (11/88) - Interface requirements for 50-baud start-stop telegraph transmission in the maritime mobile satellite service | 20 CHF |
| [R.60] Recommendation R.60 (11/88) - Conditions to be fulfilled by regenerative repeaters for start-stop signals of International Telegraph Alphabet No. 2 | 20 CHF |
| [R.62] Recommendation R.62 (11/88) - Siting of regenerative repeaters in international telex circuits | 20 CHF |
| [R.70] Recommendation R.70 (11/88) - Designation of international telegraph circuits | 20 CHF |
| [R.70 bis] Recommendation R.70 bis (11/88) - Numbering of international VFT channels | 20 CHF |
| [R.71] Recommendation R.71 (11/88) - Organization of the maintenance of international telegraph circuits | 20 CHF |
| [R.72] Recommendation R.72 (11/88) - Periodicity of maintenance measurements to be carried out on the channels of international VFT systems | 20 CHF |
| [R.73] Recommendation R.73 (11/88) - Maintenance measurements to be carried out on VFT systems | 20 CHF |
| [R.74] Recommendation R.74 (11/88) - Choice of type of telegraph distortion-measuring equipment | 20 CHF |
| [R.75] Recommendation R.75 (11/88) - Maintenance measurements on code-independent international sections of international telegraph circuits | 20 CHF |
| [R.75 bis] Recommendation R.75 bis (11/88) - Maintenance measurements of character error rate on international sections of international telegraph circuits | 20 CHF |
| [R.76] Recommendation R.76 (11/88) - Reserve channels for maintenance measurements on channels of international VFT systems | 20 CHF |
| [R.77] Recommendation R.77 (11/88) - Use of bearer circuits for voice-frequency telegraphy | 20 CHF |
| [R.78] Recommendation R.78 (11/88) - Pilot channel for AMVFT systems | 20 CHF |
| [R.79] Recommendation R.79 (11/88) - Automatic tests of transmission quality on telegraph circuits between switching centres | 20 CHF |
| [R.80] Recommendation R.80 (11/88) - Causes of disturbances to signals in VFT channels and their effect on telegraph distortion | 20 CHF |
| [R.81] Recommendation R.81 (11/88) - Maximum acceptable limit for the duration of interruption of telegraph channels arising from failure of the normal power supplies | 20 CHF |
| [R.82] Recommendation R.82 (11/88) - Appearance of false calling and clearing signals in circuits operated by switched teleprinter services | 20 CHF |
| [R.83] Recommendation R.83 (11/88) - Changes of level and interruptions in VFT channels | 20 CHF |
| [R.90] Recommendation R.90 (11/88) - Organization for locating and clearing faults in international telegraph switched networks | 20 CHF |
| [R.91] Recommendation R.91 (11/88) - General maintenance aspects for the maritime satellite telex service | 20 CHF |
| [R.100] Recommendation R.100 (03/93) - Transmission characteristics of international TDM links | 20 CHF |
| [R.101] Recommendation R.101 (03/93) - Code and speed dependent TDM system for anisochronous telegraph and data transmission using bit interleaving | 20 CHF |
| [R.102] Recommendation R.102 (03/93) - 4800 bit/s code and speed dependent and hybrid TDM systems for anisochronous telegraph and data transmission using bit interleaving | 20 CHF |
| [R.103] Recommendation R.103 (11/88) - Code and speed-dependant TDM 600 bit/s system for use in point-to-point or branch-line muldex configurations | 20 CHF |
| [R.105] Recommendation R.105 (03/93) - Duplex muldex concentrator, connecting a group of gentex and telex subscribers to a telegraph exchange by assigning virtual channels to time slots of a bit-interleaved TDM system | 20 CHF |
| [R.106] Recommendation R.106 (08/95) - Muldex unit for telegraph and low speed data transmission using TDM bit interleaving with an aggregate bit rate higher than 4800 bit/s | 20 CHF |
| [R.111] Recommendation R.111 (03/93) - Code and speed independent TDM system for anisochronous telegraph and data transmission | 20 CHF |
| [R.112] Recommendation R.112 (03/93) - TDM hybrid system for anisochronous telegraph and data transmission using bit interleaving | 20 CHF |
| [R.113] Recommendation R.113 (03/93) - Combined muldex for telegraphy and synchronous data transmission | 20 CHF |
| [R.114] Recommendation R.114 (03/93) - Numbering of international TDM channels | 20 CHF |
| [R.115] Recommendation R.115 (03/93) - Maintenance loops for TDM-systems | 20 CHF |
| [R.116] Recommendation R.116 (11/88) - Maintenance tests to be carried out on international TDM systems | 20 CHF |
| [R.117] Recommendation R.117 (03/93) - End-to-end error performance for telegraph, telex and gentex connections involving regenerative equipment | 20 CHF |
| [R.118] Recommendation R.118 (03/93) - Performance and availability monitoring in regenerative TDM | 20 CHF |
| [R.120] Recommendation R.120 (11/88) - Tolerable limits for the degree of isochronous distortion of code-independent telegraph circuits operating at modulation rates of 75, 100 and 200 bauds | 20 CHF |
| [R.121] Recommendation R.121 (11/88) - Standard limits of transmission quality for start-stop user classes of service 1 and 2 on anisochronous data networks | 20 CHF |
| [R.122] Recommendation R.122 (11/88) - Summary of transmission plans for rates up to 300 bauds | 20 CHF |
| [R.140] Recommendation R.140 (11/88) - Definitions of essential technical terms in the field of telegraph transmission | 20 CHF |
| [R.150] Recommendation R.150 (11/88) - Automatic protection switching of dual diversity bearers | 20 CHF |
