LaTeX.org

Just to complete Svend's answer, you could use label and reference to acheive this


\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{equation}\label{myeqn}
x^2 + y^2 = 1
\end{equation}

Recall equation~\eqref{myeqn}
\begin{equation}
x^2 + y^2 = 1 \tag{\ref{myeqn ...

Thank you for your help. I'm quite new to this language so the straight-up code helps a lot.

In my research paper I have very early on inside the document the following.
\begin{equation}
x^2 + y^2 = 1
\end{equation}
The auto numbering system numbered this equation as equation "2.1".

Now I want to have a way of displaying that equation once more, without having to type out the equation ...