**` ``\`` ` → ``\`` : to format a single backslash as `` `code` `` in comments, enclose it in *double backticks*.**

Same for the more general case of a `\` at the end of a <code>\`code\`</code> section:  
Comment source ` ``C:\Windows\`` ` renders to `C:\Windows\`.

A backslash at any position other than the end works fine between <code>\`single backticks\`</code>. (As well as <code>\`\`double ones\`\`</code>.)

**(**`\` is not treated as special in comment <code>\`code\`</code> sections, except when followed by a backtick while enclosed by single backticks:  
Comment source <code>\`…\\\`…\`</code> renders to <code>…\`…</code>.  
But <code>\`\`…\\\`…\`\`</code> renders to <code>…\\\`…</code>.  

If you need both a trailing backslash `\` and any number of backticks `` ` `` at the beginning, you can go dirty **hack** and separate the content backticks from the surrounding backticks with an **invisible Unicode character**, like [*zero width space*](http://www.fileformat.info/info/unicode/char/200B/index.htm): You can copy it from between the arrows: →​← (It's invisible, but it's there, I promise! ;)  To get a hold of it, copy the arrows along with it, then delete them after pasting.)

(If you need both a trailing backslash `\` and an occurrence of a double backtick ` `` ` in the interior of your `` `code` `` section, you can enclose it in triple backticks ` ```…``` ` and so on.)  
**)**

<sub>Credits: This post was helped by *juergen d*'s [answer](https://meta.stackexchange.com/questions/201663/how-do-i-format-a-backslash-as-code-with-backticks-in-comments/201665#201665) and *ThisSuitIsBlackNot*'s [comment](https://meta.stackexchange.com/questions/11388/backslash-escaped-with-backticks-rendered-incorrectly-in-comments#comment794018_11388) (on a similar question) - thanks!</sub>