2.4.1 Equations
When inserting equation-like environments, the '\label' will have a default prefix, which is controlled by the following variables:
User Option: LaTeX-equation-label
Prefix to use for 'equation' labels.
User Option: LaTeX-eqnarray-label
Prefix to use for 'eqnarray' labels.
User Option: LaTeX-amsmath-label
Prefix to use for amsmath equation labels. Amsmath equations include 'align', 'alignat', 'xalignat', 'multline', 'flalign' and 'gather'.