The EasyTimeline extension (<timeline>) supports (among many other parameters) the two parameters "till" and "tillpos". I propose to add parameter aliases "until" and "untilpos" for them and deprecate the use of "till" and "tillpos" in the documentation, so that their usage will fade out in the long run.

"till" is an archaic/historic word not used in formal written English any more (except for, apparently, in Indian English) and is considered colloquial language and bad style (except for when citing historical texts). It is still used in spoken English (and therefore also in book or song titles or in poems). In written English it can be almost always replaced by "until", sometimes also by "to" or "through". It is unfortunate to use this form as a parameter name because seeing "till" in the Wikipedia article source code encourages unaware editors to use these words also in the prose, where it will have to be corrected.

Given the long-time use of "till" in the EasyTimeline extension, we cannot simply alter the parameter name for backward compatibility reasons, but adding the suggested new forms as aliases is trivially easy and adds virtually no overhead, so that we should still go for it in order to help aid the usage of better English and less maintenance in the long run. It certainly has no priority but could be easily incorporated in a couple of minutes when someone is working on other stuff for the EasyTimeline extension anyway.