So is "P for trend" the same in principle as a common-or-garden P-value, but in a specific application i.e. odds ratios?
And can P-value, P for trend, and P-trend be regarded as interchangeable conceptually, terminologically, and in terms of statistical significance (at least)?
A pointer to an appropriate and citeable reference would be most useful, particularly if it states any differences or confirms sameness.
Edit responding to whuber's moderation
@whuber - thanks, but wouldn't an exact duplicate at least mention the topic of my question. I can see no mention of 'trend' or 'P for trend' on that page you provided. If on the other hand you know that P for trend is the same thing, then is there a citeable reference you can provide? Just to be clearer it is the use of the word 'trend' that confuses me, not the use of letter 'P'.
Another edit responding to whuber's moderation
Sorry if my question was not well formed. In attempting to provide my own answer in the hope of a confirmation, I think that the word 'trend' when talking about P-trend (e.g. for a reported result in the literature) sets the context as a P-value test for linear trend in odds ratio in logistic regression, against a categorical predictor variable. If that is correct, then this is described in standard texts as 'test for trend', in which case my copy of Kirkwood & Sterne provides a citeable reference. Hopefully this addresses whuber's concerns. Whilst the correct interpretation of P-value is very important, I was missing the context of logistic regression.