A locked box returns the last computed or edited value. Any parametric modification will be ineffective.
Procedure
To set a box on "lock" mode, select it and press b. A small cross icon appears on the upper left corner of the box.
Examples
Locked Function Boxes
The values of a locked box in a program remain in the box and are returned at the next evaluation.
A locked function always returns the same value.
Locked Factory Boxes
New input values don't affect a locked factory box.
(A) Here, a chord is edited as a C4 triad and is locked (A).
(B) When new values are assigned to the chord, the pitches don't change at the evaluation.
Automatic Locking
When an object is modified from its editor, its box gets locked automatically in order to prevent the contents to be reinitalized at a next evaluation.