When you ask a question on Stack Overflow, or Gaming.SE or RPG.SE you are asked to specify a programming language (or tool or something), a game or a gaming system when you ask a question. 

All we are looking for here is for you to tell us what system you are operating in. Christianity is not a homogenous system, it has branches, deviations and denominations. It even has branches and deviations within denominations. 

We are kidding ourselves if we think that a question and answer can be useful when they are coming from 2 different view points. It would be like answering a question asking about D&D 4e rules minutia with a D&D 3.5 rule. Anyone familiar with the D&D line of products will see that this is patently ridiculous. While operating in the same world, with many of the same features, the rules are completely different. 

Christianity is unfortunately not different, even similar denominations, possibly with even the same words in their name interpret scripture differently and come to different conclusions.

Perhaps asking for which Bible they want is a bit pedantic. Perhaps it needs to be made a bit more clear. There several different major versions of the Bible that are considered in-scope for this site:

* Mainline Protestant (66 book canon with various translations like NIV, ESV etc)
* Jehovah's Witnesses' NWT (the usual Protestant canon but with significant doctrinal differences showing through in translation)
* Catholic (mainline Protestant canon + deuterocanonical books)
* Various Orthodox canons (mainline Protestant + deuterocanonical books + more deuterocanonical books)
* The Mormon Bible (mainline protestant canon (unique Inspired Version preferred for doctrinal disputes but substitue other protestant translation) + Doctrines & Covenants and Book of Mormon).

Asking which cannon you are working in is the first step in asking what kind of interpretation you are looking for.

I'd actually see us go stricter, I would much rather see us ask for the doctrinal framework the question comes from. This actually gives a great deal more information to the answerer than simply asking for a baseline biblical cannon. 

However, at the very least the asker and the answerer must come to some agreement on the cannon, because where they arrive at the end will be determined by the cannon they use.