# Duplicate “dt” name “X” in “dl” element. Within a single “dl” element, there should not be more than one “dt” element for each name. > Canonical HTML version: https://rocketvalidator.com/html-validation/duplicate-dt-name-x-in-dl-element-within-a-single-dl-element-there-should-not-be-more-than-one-dt-element-for-each-name > Attribution: Rocket Validator (https://rocketvalidator.com) > License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) Within a `
`, each name should appear in only one `
`, so a term with several values gets one `
` followed by several `
` elements. A description list is a set of name-value groups, and the HTML specification says a single `
` should not have more than one `
` for each name. When the same term shows up twice with different values, readers can't tell whether the second entry replaces the first, adds to it, or is a mistake. Repeated terms often come from lists built from data, such as product specifications where one attribute is output twice. The validator compares the text content of each `
`. It ignores markup and leading or trailing whitespace, so `
Size
` and `
Size
` both count as `Size`. The comparison is case-sensitive, so `Size` and `size` are different names. Wrapping each group in a `
` doesn't help, because the check covers the whole `
`. Along with this warning, the validator adds a second message pointing to the first `
` with that name. If both values belong to the same term, keep one `
` and put each value in its own `
`. If the entries describe different things that share a label, give each `
` a distinct name, or move them into separate `
` elements, since the rule applies only within a single list. ## Invalid example ```html
Size
Small
Color
Red
Size
Medium
``` ## Valid example ```html
Size
Small
Medium
Color
Red
``` ## Valid example with distinct names ```html
Net weight
1.2 kg
Gross weight
1.4 kg
```