The whole of AACR2 Chapter 21 is devoted to access points, formerly often known as entry points; that is, it deals with the question of who or what is going to get an access point in the catalogue. As I mentioned earlier, AACR2 still maintains the distinction between main entry and added entries; if it did not do so, most of this chapter could be swept away, because all access points would be equal. In an online catalogue they are effectively equal anyway, but as long as the rules remain as they are we need to understand how they work.

Online catalogues also usually provide various other kinds of access points which are not mentioned by AACR2 at all, such as Keyword and Publisher. And remember that AACR2 does not deal with subject access in any way.

As with so many sections of AACR2, the basics are very simple, but they can often be obscured by the detail which is necessary to deal with unusual cases.

The first thing to note is that, unlike in the description, we are no longer tied closely to particular sources of information in the item itself; although the item itself naturally still has priority, we are allowed to use external sources if required. The order of sources is

In practice this seldom makes any difference, but, for example, in the case of an anonymous work whose authorship has subsequently been established, it does allow us to make the entry under the actual author's name even though it does not appear in the item itself.

The next thing is that, because AACR2 breaks down the task of cataloguing into as many separate operations as possible, the actual form of the access points is not discussed at all in this chapter. As I said at the beginning (pp. 12–13), there is a difference between deciding that Shakespeare is going to be the main entry and establishing the actual form of his name that we are going to use. This means that whenever an access point is referred to in AACR2 Chapter 21, the actual form of the access point cannot be mentioned because that is dealt with in other chapters.