I have discovered that the following two tags are too similar to each other:

- riemann-zeta-function, with 299 questions tagged, has the description

The Riemann zeta function is the function of one complex variable $s$ defined by the series $\zeta(s) = \sum_{n \geq 1} \frac{1}{n^s}$ when $\operatorname{Re}(s) > 1$. It admits a meromorphic continuation to $\mathbb{C}$ with only a simple pole at $1$. This function satisfies a functional equation relating the values at $s$ and $1-s$. This is the most simple example of an $L$-function and a central object of number theory.

and no tag wiki;

- zeta-functions, with 195 questions tagged, has the description

The Riemann zeta function is defined as the analytic continuation of the function defined for $\sigma > 1$ by the sum of the preceding series.

and tag wiki

The Riemann zeta function, $\zeta(s)$, is a function of a complex variable $s$ that analytically continues the sum of the infinite series

$$\zeta(s) =\sum_{n=1}^\infty\frac{1}{n^s}$$

which converges when the real part of $s$ is greater than $1$.

There are two problems here:

does it make sense to have one tag dedicated to just the Riemann $\zeta$, and a single other one for the rest of the $\zeta$ functions? A single tag for all these functions should suffice.

if we still want tags to distinguish between Riemann and "non-Riemann" $\zeta$ functions, then the latter class of functions should be correctly described in the tag description and tag wiki - a thing that does not currently happen with the latter tag.

My suggestion is to just melt the former tag into the latter, and automatically retag all the questions.