The Old NetISSUE #16 of 60

xhtml 1.0 · strict · transitional · frameset

Pixel PeteVSQuirks Mode

Pixel Pete saysXHTML 1.0 came in three flavors: Strict, Transitional, and Frameset.

XHTML 1.0 reformulated HTML 4.01 as XML in three DTDs: Strict (no presentational markup — CSS only), Transitional (allowed legacy attributes like bgcolor for migration), and Frameset (for the old framed layouts). Strict was the aspirational target; Transitional was what most sites actually used.

Power-ups you unlock

Strict: structure only, CSS for presentation
Transitional: legacy presentational attributes allowed
Frameset: for old frame-based layouts
Pick the DTD via the doctype

Quirks Mode attacks — common mistakes

Using Transitional as a crutch for presentational markup
Mismatching doctype and actual markup
Choosing Frameset for non-framed pages

Boss battleDecide which 1.0 flavor a clean, CSS-styled page should declare.

Example code

<!doctype html><html><head><meta charset="utf-8"></head>
<body style="background:#06040d;color:#e6e0ff;font-family:monospace;padding:20px"><pre>XHTML 1.0 Strict        → CSS-only, no bgcolor
XHTML 1.0 Transitional  → legacy attrs allowed
XHTML 1.0 Frameset      → &lt;frameset&gt; layouts</pre></body></html>

▶ Open the interactive comic issue

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