Standard CSS counters, that is counter-reset, counter-increment, counter() and counters(), are fully supported by XXE. However, for most uses, we also have a simpler, faster because purely declarative, alternative to standard CSS counters.

Proprietary simple-counter() and simple-counters() may be used everywhere you use counter() and counters() and this, with a similar syntax: simple-counters(n, "."), simple-counter(n, upper-roman), etc. But, being purely declarative, you don't need to specify simple-counter-reset or simple-counter-increment in order to declare and update them.

Just like counter and counters, simple-counter and simple-counters are supported inside the content property. However their semantics are very different: the name of the counter specifies the non-formatted value of the counter.

Example 1 (XHTML):

ol > li:before {
    display: marker;
    content: simple-counter(n, decimal);
    font-weight: bold;
}

In the previous example, the counter name is n (single letter 'n', any letter is OK) which specifies that the counter value is the rank of li within its parent element (an ol).

Example 2 (DocBook):

sect3 > title:before {
    content: simple-counter(nnn-) " ";
}

In the previous example, the counter name is nnn- (3 letters followed by a dash) which specifies that the counter segmented value must be built as follows: