# The first occurrence of “dt” name “X” was here.
> Canonical HTML version: https://rocketvalidator.com/html-validation/the-first-occurrence-of-dt-name-x-was-here
> Attribution: Rocket Validator (https://rocketvalidator.com)
> License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
This message points to the first `` in a `` whose name is repeated later in the same list.
It always comes with a duplicate `dt` name warning on the later `- `. Together, the two messages show where each copy of the term is, so you can compare them and decide which one to keep. The HTML specification says a single `
` should not have more than one `- ` for each name.
The validator compares the text content of each `
- `. It ignores markup and leading or trailing whitespace, so `
- Size
` and `- Size
` have the same name. The comparison is case-sensitive, so `Size` and `size` don't clash.
The first `- ` is usually fine on its own; the fix goes where the name repeats. If both entries describe the same term, keep one `
- ` and give each value its own `
- `. If they describe different things, give each `
- ` a distinct name. Once every name in the list is unique, both messages go away.
## Invalid example
```html
- Size
- Small
- Color
- Red
- Size
- Medium
```
## Valid example
```html
- Size
- Small
- Medium
- Color
- Red
```