Block elements

P paragraphs
The paragraph element requires a start tag, but the end tag can always be omitted. Use the ALIGN attribute to set the text alignment within a paragraph, e.g. <P ALIGN=RIGHT>
UL unordered lists
These require start and end tags, and contain one or more LI elements representing individual list items.
OL ordered (i.e. numbered) lists
These require start and end tags, and contain one or more LI elements representing individual list items.
DL definition lists
These require start and end tags and contain DT elements that give the terms, and DD elements that give corresponding definitions.
PRE preformatted text
Requires start and end tags. These elements are rendered with a monospaced font and preserve layout defined by whitespace and line break characters.
DIV document divisions
Requires start and end tags. It is used with the ALIGN attribute to set the text alignment of the block elements it contains. ALIGN can be one of LEFT, CENTER or RIGHT.
CENTER text alignment
Requires start and end tags. It is used to center text lines enclosed by the CENTER element. See DIV for a more general solution.
BLOCKQUOTE quoted passage
Requires start and end tags. It is used to enclose extended quotations and is typically rendered with indented margins.
FORM fill-out forms
Requires start and end tags. This element is used to define a fill-out form for processing by HTTP servers. The attributes are ACTION, METHOD and ENCTYPE. Form elements can't be nested.
ISINDEX primitive HTML forms
Not a container, so the end tag is forbidden. This predates FORM and is used for simple kinds of forms which have a single text input field, implied by this element. A single ISINDEX can appear in the document head or body.
HR horizontal rules
Not a container, so the end tag is forbidden. attributes are ALIGN, NOSHADE, SIZE and WIDTH.
TABLE can be nested
Requires start and end tags. Each table starts with an optional CAPTION followed by one or more TR elements defining table rows. Each row has one or more cells defined by TH or TD elements. attributes for TABLE elements are WIDTH, BORDER, CELLSPACING and CELLPADDING.