In an online situation such as the Web, there need be no display of long sequences of subject representations. It is necessary to display the contents of a facet, and consequently issue (c) may be relevant, and will be discussed below. One strength of a computer system is that facets can be displayed in any sequence, and terms from them combined in any order, so that issues (a) and (b) become irrelevant, and a notation is not needed. As hinted earlier, there may be an issue as to the time sequence in which various facets are displayed, and this will be considered when we come to look at facet implementations on the Web.