ITU-T RECOMMENDATION E.121 PICTOGRAMS AND SYMBOLS TO ASSIST USERS OF THE TELEPHONE SERVICE
1 General definitions and guidelines
    1.1 Definitions
    1.2 Pictograms and symbols as an alternative to written text
    1.3 Guidelines for design
    1.4 Guidelines for testing
    1.5 Standardization
    1.6 Design specifications
2 Specific recommendations
    2.1 Symbol for telephone
    2.2 Symbol for information
    2.3 Symbols for emergency numbers
    2.4 Graphical representation of audible tones
    2.5 Symbols for supplementary services
    2.6 Pictographic instructions for payphones
    2.7 Symbol for facsimile
    2.8 Symbol of access for the physically handicapped
    2.9 Symbol for special facilities for the deaf and hard of hearing
ANNEX A
ANNEX B
References