This is a convenience template for the zero-width, optional-whitespace character, U+200C<reserved-200C> (‌).
It is completely invisible in display, but has the effect of acting as a breaking point at an otherwise non-breaking situation, e.g. within continuous text inside a word that otherwise would possibly break.
In some browsers (known: IE 7.0.5730.13) the ZWNJ character shows as a pipe-like symbol, shown here immediately to the left of the comma in the accompanying diagram. Could be in styled heading only. Example from the Wikipedia Village pump (technical) (full discussion)