HTML Guide - issues tagged as rel

A “link” element with an “as” attribute must have a “rel” attribute that contains the value “preload” or the value “modulepreload”.

The error message indicates that the <link> element contains an as attribute, but its rel attribute does not hold the correct value. According to the HTML specification, when using the as attribute, the rel attribute must be set to "preload" or "modulepreload".

Explanation

The as attribute is used to specify the type of content being loaded, which helps the browser to handle it appropriately. To preload resources, you need to specify the rel attribute with the value "preload" (for general resources) or "modulepreload" (specifically for JavaScript modules).

Example with preload:

If you are preloading a stylesheet, the rel attribute should be set to "preload":

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Correct Usage of Link with as Attribute</title>
    <link rel="preload" href="styles.css" as="style">
</head>
<body>
    <p>Hello, World!</p>
</body>
</html>

Example with modulepreload:

If you are preloading a JavaScript module, the rel attribute should be set to "modulepreload":

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Correct Usage of Link with Modulepreload</title>
    <link rel="modulepreload" href="script.js" as="script">
</head>
<body>
    <p>Hello, World!</p>
</body>
</html>

Bad value “X” for attribute “rel” on element “Y”: The string “X” is not an absolute URL.

The rel attribute defines the relationship between a linked resource and the current document. Valid on <link>, <a>, <area>, and <form>, the supported values depend on the element on which the attribute is found.

Here’s an example of using the rel attribute to link a document to a CSS stylesheet:

<link rel="stylesheet" href="default.css" />

Here’s an example os using the rel attribute to tell search engine spiders to ignore the link relationship with another document:

<a href="https://example.com" rel="nofollow">more info</a>

Element “link” is missing one or more of the following attributes: “href”, “itemprop”, “property”, “rel”, “resource”.

A <link> element must include at least one of the attributes href, rel, itemprop, property, or resource.

The <link> element is used to define the relationship between the current document and an external resource, most commonly for linking stylesheets (rel="stylesheet") or providing metadata. According to the HTML specification, at least one of the attributes href, rel, itemprop, property, or resource must be present so the browser or validator knows the purpose of the link.

Correct usage with rel and href:

<link rel="stylesheet" href="styles.css">

Correct usage with property:

<link property="og:image" href="image.png">

Element “link” is missing one or more of the following attributes: “itemprop”, “property”, “rel”.

link elements are used to link to external resources, such as stylesheets, scripts, and icons. Including relevant attributes in the link element helps provide additional information about the linked resource.

rel: The rel attribute specifies the relationship between the current document and the linked resource, and can also provide additional information about the type of linked resource. For example, using rel="stylesheet" for a linked CSS file or rel="icon" for a linked favicon.
itemprop: If the linked resource is an HTML document or a microdata vocabulary like Schema.org, use itemprop to specify properties the linked document or vocabulary defines.
property: If the linked resource is an RDF resource, use property to provide metadata about the relationship between the current document and the resource being linked.

Example with rel attribute:

<head>
  <link rel="stylesheet" href="styles.css">
  <!-- Other meta tags -->
</head>

Example with itemprop and property attributes:

<head>
  <link itemprop="mentions" href="https://example.com/"> 
  <link property="schema:citation" href="https://example.com/article.html">
   <!-- Other meta tags -->
</head>

By adding itemprop, property, or rel as necessary, you can ensure your link elements provide appropriate context and semantic meaning to your HTML document.