Internet Explorer 6 and Internet Explorer 7 treat <hr> elements as inline elements when the HTML 4 specification clearly indicates that <hr> elements are block-level elements.

Show the default display for <hr> according to your browser

unknown or not available unknown or not available
The correct answer should be, must be block, not inline.

Actual (live) results in your browser:

This green horizontal rule should be on the left

This orange horizontal rule should be aligned according to the default alignment (usually center) for <hr>

This blue horizontal rule should be in the right

Expected results (2 screenshot 910px):

This orange horizontal rule should be aligned according to the default alignment (usually center) for <hr>

Firefox 2.0.0.8, Firefox 3.0.5, Safari 3.0.3, Konqueror 3.5.2, Konqueror 4.1.3, Seamonkey 1.x, Seamonkey 2.x, K-meleon 1.x, Epiphany 2.20, NS 7.0, NS 7.2, Hv3 TKHTML alpha 16, Amaya 11.1 all pass these 3 tests.