3 Definitions and abbreviations
22.0303GPPMan-Machine Interface (MMI) of the User Equipment (UE)TS
3.1 Definitions
For the purposes of the present document, the following definition applies:
Directory Number: A string consisting of one or more of the characters from the set {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, *, #, a, b, c} associated with a nature of address indicator and number plan indicator. When using the public MMI for the control of supplementary services however, * and # cannot be part of any SC or SI field.
NOTE 1: No such restriction on the SC and SI fields exists when using other (e.g. menu-driven) MMI for the control of supplementary services.
NOTE 2: When using the public MMI, certain limitations on the use of one and two digit directory numbers may apply. The use of other MMI can remove these restrictions.
NOTE 3: This definition is not intended to require the support of all these characters in the MMI itself.
3.2 Abbreviations
For the purposes of the present document, the abbreviations listed in 3GPP TR 21.905 [18] apply.