The `@` issue is being dealt with in two different ways.  First, any unknown tags now get consumed into the description of the previous tag.

```
@example
This text is in the example and so is the following
@unknown tag. But the following
@known tag will not be ignored.
```

Second, all tags are ignored inside GFM back-tick fenced code blocks.

    The following code block can contain tags that are ignored by the parser
    ```
      @ignore-me This tag is ignored, even if it is a known tag
    ```