Zeichencodierung HTML5: 512 oder 1024 Byte

[1UnitedPower]

Meine Herren,

Welche Angabe ist korrekt?

Laut whatwg 1024:

"The authoring conformance requirements for character encoding declarations limit them to only appearing in the first 1024 bytes. User agents are therefore encouraged to use the prescan algorithm below (as invoked by these steps) on the first 1024 bytes, but not to stall beyond that."