I7 coding problem. won't understand the "token".

This is the problem code.

[code]the pass_code is a text that varies.

accessing is an action applying to nothing. understand “[the pass_code]” as accessing.[/code]

this is the error

[code]This is the report produced by Inform 7 (build 6G60) on its most recent run through:

Problem. I was unable to understand what you meant by the grammar token ‘the pass_code’ in the sentence ‘understand “[the pass_code]” as accessing’ .

You can’t turn any variable into a grammar token. Grammar tokens stand in for kinds. The kind of the pass_code variable is text. So you want something like this:

[code]A pass_code is a text that varies.

Accessing is an action applying to one topic.
Understand “[text]” as accessing.[/code]
Note that the action does apply to something, viz. the text that the text token holds a place for.

I suppose you’d also better put some condition on the understand clause (like »Understand “[text]” as accessing while in the Entrance to the Secret Vault.»), or the accessing rules will fire as soon as a player misspells a verb—possibly long before he/she knows there is anything in the game to access by a password.

You could make the condition be when the command actually matches the code. Unfortunately I was not able to find a concise way to do this. This is the best I’ve got:

The pass_code is a text that varies. The pass_code is "xyzzy".

Accessing is an action applying to one topic. 
Understand "[text]" as accessing when command matches code.

To decide whether command matches code:
	let T be an indexed text;
	now T is the player's command;
	if T is the pass_code:
		decide yes.

If the code words are fixed, you could just make them into things:

A pass-code is a kind of thing.  Xyzzy is a pass-code.  Frotz is a pass-code.
Accessing is an action applying to one visible thing.
Understand "[any pass-code]" as accessing.

If you want to be able to change the pass-codes at runtime (say, by letting the player enter a new code), then you can work around the problem by giving your pass-codes a variable name, like this:

The special code is a privately-named pass-code.
The special code has some indexed text called the code-word.
The code-word of the special code is "plugh".
Understand the code-word property as describing the special code.

Thanks all. Zarf’s code looks to be about what I was looking for.