The HTML <ol> Element (or HTML Ordered List Element) represents an ordered list of items. Typically, ordered-list items are displayed with a preceding numbering, which can be of any form, like numerals, letters or Romans numerals or even simple bullets. This numbered style is not defined in the HTML description of the page, but in its associated CSS, using the list-style-type property.

There is no limitation to the depth and imbrication of lists defined with the <ol> and <ul> elements.

Usage note: 
The <ol> and <ul> both represent a list of items. They differ in the way that, with the <ol> element, the order is meaningful. As a rule of thumb to determine which one to use, try changing the order of the list items; if the meaning is changed, the <ol> element should be used, else the <ul> is adequate.

Content categories:
Flow content, and if the <ol> element's children include at least one <li> element, palpable content.

Permitted content:
Zero or more <li> elements.

Tag omission:
None, both the starting and ending tag are mandatory.

Permitted parent elements:
Any element that accepts flow content.

DOM interface:
HTMLOListElement
