Reissner-Nordström
The Reissner-Nordström metric is a class of spherically symmetric electrovacuum spacetimes parametrized by two characteristic lengths, the Schwarzschild radius $r_s$ and the length scale $r_Q$, or alternatively a mass $M$ and charge $Q$, with the relation
\begin{eqnarray} r_s &=& \frac{2GM}{c^2}\\ r_Q &=& \frac{Q^2 G}{4\pi \varepsilon_0 c^4} \end{eqnarray}1. History
2. Topology
3. Metrics and coordinates
$$ds^2 = (1 - \frac{r_s}{r} + \frac{r_Q}{r}) dt^2 - (1 - \frac{r_s}{r} + \frac{r_Q}{r})^{-1} dr^2 - r^2 (d\theta^2 + \sin^2 \theta d\varphi^2)$$4. Tensor quantities
5. Symmetries
$\partial_t$, $\partial_\theta$, $\partial_\varphi$6. Stress-energy tensor
7. Curves
8. Equations
9. Causal structure
10. Asymptotic structure
11. Energy conditions
12. Limits and related spacetimes
In the limit $Q = 0$, it reduces to the Schwarzschild metric.