Usability

Plone differentiates itself on usability. The intuitiveness of the user interface is what attracts people to Plone the most.

There are many subtle principles of usability that won't be discussed here, but there is one golden rule: **be consistent**. Do not introduce new UI metaphors without a damned good reason. Re-use existing HTML and CSS patterns. Make sure things look consistent.

Also, you must think about the purpose of a UI element and avoid overloading it. The classic example is that people use portlets for static UI elements. Remember that portlets can be removed and re-ordered by users, so depending on them for functionality is not a very good idea.

Similarly, the personal bar (the blue one with 'my folder', 'preferences' etc.) is used for "personal" items, related to the user, not for site-wide actions. The site actions are used for ... site-wide actions like the sitemap and the site setup, and so on.

Usability often comes down to taste and finesse. If in doubt, ask on the "developer list":/support#developers, do your best, and don't be offended if limi changes your carefully crafted HTML.