If the field you want to lock does not have that switch as part of its syntax, here’s another way: Click in the field and press Ctrl F11.
To confirm that the field has been locked, right-click it; the Update Field command is unavailable on the menu that appears.
If neither of these methods works, check to make sure the field is not locked.
On the Home tab, click the Find arrow, click Go To, and choose Field from the Go to What list and click Next to go to the next field. Doing so copies its current value into the document and then deletes the field placeholder.
Before unlinking a field, update it one last time (F9) if needed.
Now that you know about the fields you can insert, let’s look at how you can edit the properties of a field and update its values after insertion.
Most fields are not automatically updated each time you open or save the document.
Field Doesn’t Update Remember, most fields do not update automatically.