When someone says that a minor first step will lead to continually major consequences, this is called a slippery slope argument. Starting at the top of a slippery slope means that you'll whizz down it ever more quickly. But since the metaphorical slope is very often not slippery, this argument is a common fallacy.
Designing web pages often incurs a similar fallacy. You start by giving a page a grand title, and find that it's far more grand than it deserves. So for example a page that I wrote containing a bit of advice about giving overviews early was initially titled Principles of Design. But there was only one principle, and it was a very specific one, so it was more suitable instead to call the page Give Overviews Early. Therefore:
Or in other words, sticky slope design is the idea that though a page may progress to be more general and inclusive, you have to describe the page as it is, and not as you'd like it to be. Of course a “further plans” section is fine, but when you're titling the page and structuring it and so on, it's difficult to avoid promising more than the page really delivers.
Catching this in practice is often very difficult, because we're always trying to classify things even without noticing it. Once I wanted to write up a calculation about how far fireflies are visible at night, for example. But should the page be considered about fireflies, or about how far things are visible at night? It's impossible to tell whether further accretions, if any, would be more and more about fireflies, or more and more about nocturnal visibility.
This category drift is especially tricky when considering URI design, of course: should you choose “fireflies” or “visibility”? It also relates to the problem of branding. Since branding is orthogonal to the content and more likely to change, branding ought not to be used as part of a page's categorisation and title, or any other of its prominent metadata.