This is a rarely used list tag that generally has the same sort of effect as the <ul> tag.
Microsoft Word 97 uses multiple nested <dir> ... </dir> tags without <li> items to control text indentation when saving a word processed document in HTML.
The tag was intended to produce multi-column lists but no browser seems to do this, which is a pity. The only way to produce multi-column output is via tables which are much harder to maintain than a simple list.The list below is unlikely to change (unless Puerto Rico gets statehood) but would look much nicer in multi-column format. It could have been done as a table but this would be cumbersome for data that isn't really tabular in character.
Here's an example
Browsers
MOS3 and IE3 render the list with the same bullets as used
for all levels of <ul> list.
ARA and NN render the list with the same bullets as used for
a top level <ul> list.
OP2 renders the list without any bullets or other distinctive marks.
All browsers produce a single column list.
The compact attribute has no effect.