It is possible to replace previous received SMS messages on the
handset using a special feature called replacement sets. When a
message is received with identical replacement set (REPLACE
parameter) and sender-ID (SND parameter), it will replace any
matching previously received message in the inbox.
Typical usage of this is applications where several SMS messages are
sent to the same user, and only the latest is relevant at all times. This
can be a stock-ticker notification service or a one-time password
service. The subscriber will not get is Inbox flooded even if the
number of received messages is large.
Message 1: Message 2: Message 3:
TXT=Test1 TXT=Test2 TXT=Test3
REPLACE=3 REPLACE=3 REPLACE=4
SND=123456 SND=123456 SND=123456
Message 1 will receive as normal. Message 2 will replace message 1 in
the inbox since REPLACE and SND matches those of message 1.
Message 3 will receive as normal since REPLACE is different from
message 1 and 2.
This feature depends on whether the handset supports it or not. If not
supported, the message will be received as normal. There may also be
limited support in certain networks.