<span class="sortkey">-{{{1}}} </span>−{{{1}}}

Use this template to display a number with the HTML character entity − but preceded by that same number with an ASCII hyphen-minus as non-visible text for correct numerical sorting in a sortable table.

Example: "{{neg|1.23}}" gives "-1.23 −1.23" [1]. (Click on the link to see the full text generated, including non-visible portions.)