rfc/004-optimized-for/index.html


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94

<!doctype html>
<html>
<head>
  <title>Dillo RFC 004 - Optimized-for META tag</title>
<style>
body {
  background: white;
  line-height: 1.5;
  margin: 3em;
  font-family: sans-serif;
  max-width: 72ch;
}
h1 { margin-bottom: 1em; }
header { border: solid 1px #ddd; background: #f5f5f5; padding: 0.25em 1em }
dt { font-weight: bold }
dd { margin-left: 2ch; }
pre { padding-left: 4ch; }
</style>
</head>
<body>

<h1>Dillo RFC 004 - Optimized-for META tag</h1>

<header>
<dl>
<dt>State</dt><dd>Draft</dd>
<dt>Date</dt><dd>Draft on 2025-08-02</dd>
<dt>Author</dt><dd>Rodrigo Arias Mallo
  &lt;<a href="mailto:rodarima@gmail.com">rodarima@gmail.com</a>&gt;</dd>
</dl>
</header>

<h2>Abstract</h2>

<blockquote>
<p>This document proposes the <em>optimized-for</em> meta tag to indicate
web browsers that the authors have explicitly made an effort to improve the page
for an specific browser.</p>
</blockquote>

<h2>Background</h2>

<p>Some HTML authors have optimized their websites by removing features that are
not yet supported in Dillo or by adjusting the CSS rules so that some
limitations or bugs are not present.

<p>The effect of this behavior causes pages to appear well rendered in Dillo,
which is a priori an improvement in the overall experience. However, if a page
has been optimized or not for a given browser is often not easy to determine
unless explicitly stated.

<p>When testing Dillo on a set of real websites, we need to be sure that those
pages are not optimized for Dillo, as otherwise it would skew our perception.

<h2>Proposal</h2>

<p>To address this issue, web authors are encouraged to tag their pages if they
were optimized for Dillo (or other web browsers). We propose the following meta
tag:</p>

<pre><code>
&lt;meta name="optimized-for" content="dillo"&gt;
</code></pre>

<p>Multiple entries must be specified in multiple tags:

<pre><code>
&lt;meta name="optimized-for" content="dillo"&gt;
&lt;meta name="optimized-for" content="elinks"&gt;
&lt;meta name="optimized-for" content="w3m"&gt;
</code></pre>

<p>The version of the web browser can be <em>optionally</em> specified after the
<code>/</code> separator, like it would appear in the <code>User-Agent</code>
HTTP header:

<pre><code>
&lt;meta name="optimized-for" content="dillo/3.2.0"&gt;
&lt;meta name="optimized-for" content="elinks/0.11"&gt;
</code></pre>

<p>Including the version is encouraged, as it will let developers know which
features were available when the optimization was performed. Multiple version
lines can also be provided for the same web browser.

<h2>Parsing</h2>

<p>When a web browser loads an HTML page which has an <code>optimized-for</code>
meta tag that matches the current browser, it can <em>optionally</em> show such
information in the user interface, so that developers are aware that they are
seeing a optimized page for that browser.

</body>
</html>