none.

To enable folding:
Preferences->General->Editors->Structured Text Editors->Appearance->Enable folding
Context menu of editor's vertical ruler->Folding->Enable Folding

Here is some information on what constitutes a foldable region

• folding for xml creates folding region for all xml tags
• folding for html creates folding region for head, body, script, style, table tags
• folding for jsp creates folding region for jsp scriptlet tags
• folding for css creates folding region for all style rules

Relevant bugs:

• Bug 73271
• Bug 85776

• Verify Enable folding preference turns on/off folding and removes folding markers in vertical ruler
• Verify Folding vertical ruler menu (Enable Folding, Expand All, Collapse All)
• Verify when create new foldable region, code folding markers appear when create new foldable region via
  • type in a region by hand
  • insert via outline view
  • insert via content assist
  • insert via copy/paste
• Verify when delete foldable region, folding markers disappear
• Verify typing and pasting text before/after folded region types normally
• Verify typing and pasting text in the middle of folded region expands folded region
• Verify big document changes such as format/cleanup/revert/undo don't break folding
• Verify Save As different content type and New Editor (so 2 editors open on same file) do not break the editor

org.eclipse.wst.sse
org.eclipse.wst.xml
org.eclipse.wst.html
org.eclipse.wst.css
org.eclipse.wst.dtd
org.eclipse.wst.javascript
org.eclipse.jst.jsp