Sony MSAC-US40 Operating Instructions Manual page 36

Write-protecting data
A "Memory Stick" is equipped with a write-protect switch to ensure that
important data is not deleted by mistake. (Some of "Memory Stick"
("Memory Stick Duo") are not equipped with a write-protect switch. If you
use a "Memory Stick" ("Memory Stick Duo") unequipped with the write-
protect switch, be careful not to write data or delete data by mistake.)
Sliding this switch to the left or right enables or prevents writing of data to
the "Memory Stick."
• Write enable
Data can be written.
• Write protect
When the switch is moved to the right, the condition becomes the one in
which data cannot be written to the "Memory Stick." Data can be read
out but writing is prevented.
Underside of "Memory Stick"
Data read/write speed
The data read/write speed differs depending on the "Memory Stick" and
product combination that you are using.
Write enable Write protect
36-GB