{{Conjecture/doc}} is a template that flags articles whose subjects' names do not actually appear within a valid narrative.
What this template is
This template merely announces to readers that we've had to make up a name for a thing because story writers failed to. The perfect example is the article stingray, which is about the main threat in the story Planet of the Dead. Davies and Roberts did not flatly name the creatures in the Easter 2009 special, yet they clearly exist in the DWU and so are worthy of an article here. We had to name the article something, so we picked a logical name and went with that.
This template merely makes it clear to readers that there is no actual name for the topic in a valid source.
Sometimes, when this is clearest or improves searchability, we draw a conjectural name from a script, deleted scene or other real-world material which is not, itself, a valid source. Note that such conjectural names should not be used in the in-universe sections of the page.
What this template is not
This template does not attempt to correct the situation. It is not a sign of a problem, any more than {{real world}} or {{invalid}}. It is saying that there is no correct name.
It is not saying that we've named the page wrongly.
Therefore, you should never use this template in conjunction with {{rename}}. If you can propose a new article name, then the article title is no longer conjectural—it's just wrong. Put another way, {{rename}} trumps {{conjecture}}.
Of course, there may be times where you want to use {{rename}} to propose a new conjectural name for an article. For instance, maybe you feel like "manta ray" is a better name for stingray. For the duration of that proposal, {{rename}} should supplant—and not be merely added to—{{conjecture}}. After the rename discussion has been resolved, {{conjecture}} would return.
Usage
To use, just type {{conjecture}} as the first word of an article. It is vital that the template be the the very first word of the article, prior even to any infobox templates.
Check the behind the scenes section, the revision history and discussion page for additional comments on this article's title.