A variable can be any length.
That said, the best variables are short. Short variables are easier for the user to see and process when encountered in a document.
When a variable exceeds a certain length, it becomes unwieldy. There is no definitive size when this occurs, but Pathagoras suggests 40 characters as the 'max.' (Indeed, '40' is set as the default maximum variable length when you install Pathagoras)
Can a variable be 'too short'? Yes. When the replacement value is not clearly suggested by the variable, it is too short. The variable '[NOC]' (standing for, perhaps, Name of Client) is probably too short. Why? Few people (especially new staff just learning your systems) would know what that abbreviation means. ("[DOB]" may work because it somewhat has a universal acceptance as the abbreviation for Date of Birth.)
Similarly, "[Name]" is probably too short for most situations. Who's name is being called for? On the other hand, "[Name of Client]" is perfect. So would be "[Name of Our Client]", "[Client Name]", "[ClientName]", and a myriad of other choice. "[Name of our client as indicated on the first line of the Client Intake Sheet]" is 'legal', but too long for 'best practice.' (What about [Client's Name]? See the discussion here as to why quotation marks and apostrophes are a 'bad idea' within variable names.)
Q. I know that my clauses are all short, yet Pathagoras tells me otherwise. What's happening?
•Most likely you are missing bracket to close the variable. Since Pathagoras cannot tell where the variable ends, it assumes that the 'rest of the document' is the variable. Pathagoras reports this back to you via the screen shown below.
•Also likely: you have some explanatory text (perhaps from a legacy source) that was enclosed within the same bracketing set you use for your variables. Pathagoras cannot distinguish between such explanatory text and a variable that you have created.
Q. So what options are available to me?
•If you encounter a 'variable is too long' error during a document assembly session, Pathagoras will pop up this screen as it is scanning the document for variables:
Study the available options. Make a selection. The selections will hold for the remainder of the Scanning session. (Exception: if you set a new max length, that will permanently reset the value.)
•Regardless of the choices you make while in 'live' operation, you should rethink the underlying form and make changes as appropriate. If the source text is a missing bracket, you need to go into the source document to add it.
•If the problem is 'explanatory text' from legacy sources, decide if you need to retain that text. If you do, then open the source text and change the enclosing characters to something other than the one used to identify variables.
•If the variable is 'correct' but just longer than the default maximum, either reduce the size of the variable in the source text to the 'max length' or increase the default maximum length for variables. You would accomplish the latter in the Instant Database Tools screen.
•You can tell Pathagoras to completely ignore variables that exceed the maximum length. This is also done in the Instant Database Tools screen.