This vital work must now be done by a navigation approach that creates the best possible context. If you are driving you get used not just to what the road signs say, but also their size, shape and colour. If you are driving along following a set of signs and suddenly they change shape, size and colour, your immediate response is one of confusion and hesitation. Thankfully, few countries change the design of their signs from region to region or town to town. Not so on the web, where navigation can change in an ad hoc manner within a particular website.
Readers often turn to navigation when they're confused or lost.
Don't confuse them even more by displaying inconsistent or unfamiliar navigation design. For example, if you decide to put navigation in the left column, don't then switch it to the right column in another section of the website. Consistency of language is critical for successful navigation. That only serves to confuse the reader. Establish the language and terms you are going to use in your navigation approach and use them exactly as you have defined.