Motorola C51 COMMUNICATION SYSTEM-SD7505 User Manual page 36

If a phonebook entry includes multiple phone numbers, multiple records are created, one
for each phone number. Phonebook downloads can transfer up to 250 entries.
A downloaded phonebook cannot be modified by a C51 cordless handset. Downloaded
phonebook entries can only be viewed by a C51 cordless handset. The SD7505 phonebook
can only be updated by performing a new download from the mobile phone.
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