Can't remember the word for literal setting of the variables

Question

It is programming related.

Well, I have a phrase, something like:

If the parameter wasn't set ..., the default value should be used.

I can't remember the word people usually use here. Something like "wasn't set literally" or "manually". It's on the tip of my tongue. Really frustrating.

Answer 1

The usual word for setting a variable is explicitly.

precisely and clearly expressed or readily observable; leaving nothing to implication

[WordNet via OneLook]

The default value is implied (left to implication), where it is not directly expressed.