Samsung SCH i830 - Manual (Page 76)

76
Section 6
SIM SMS
SIM SMS stores up to 15 sent or received SMS messages on
the SIM card. For text messaging procedures, see "Create
and Send a Text Message" on page 81.
SIM Own Number
The SIM Own Number option provides the ability to store
phone numbers that are used with this SIM card. If you
have more than one phone that uses the same SIM card,
this information may be stored here.