There are currently ordering issues with formatters.

Enclosed is a list of desired formatters. Please comment if you have any others. From here I can figure out how to group them into phases.

Plain Text

Convert text separated by two new line characters into two HTML P elements
Convert text separated by one new line character into text separated by a HTML BR element
Escape HTML characters
HTML
Implicit validation
- p>h1 => p+h1
- =>
Replace non-breaking space HTML entities with normal space (when appropriate?)
Translating node names e.g. b => strong
Remove HTML comments
Remove inner text of SCRIPT and STYLE elements (configurable?)

<p>1</p>
<p>2</p>
=>
<p>1</p><p>2</p>

Sanitise elements according to whitelist (when removing block elements, replace with configurable block element)
- Removing non-whitelisted elements by node name
- Removing non-whitelisted attributes
- Removing non-whitelisted attribute values (lists, strings, regular expressions)
Reposition invalid nested block elements (configurable block elements)
Condense whitespace around block elements to avoid erroneous text nodes (configurable block elements)
Consolidate consecutive text nodes
Wrap isolated text in P elements (if in block mode)
Insert BRs into elements to ensure they are selectable
Exporters
Remove trailing BRs

guardian / scribe