HTC One mini User Manual page 77

77 Messages
How do I protect a message from being deleted?
You can lock a message so that it will not be deleted even if you delete the
other messages in the conversation.
1. On the Messages screen, tap a contact (or phone number) to display the
exchange of messages with that contact.
2. Tap the message that you want to lock.
3. Tap Lock message on the options menu. A lock icon is displayed.