Here are some common settings for HTMLawed that can be used as a more lenient 'filtered html' format for trusted editors that need a simple WYSIWYG. This configuration allows images, which can be a security risk. If you don't understand the risk, then leave Drupal's defaults the way they are and perhaps try to work with the Full HTML format or use CSS classes and stylesheets.

The htmLawed module enables the use of the htmLawed(X)HTML filter/purifier with text/input formats.

This module lets you use very fine grained html filtering.

See /docs/common-htmlawed-settings for common settings.

Here are some examples of using Drupal's states API. It shows the use of OR and XOR (which only work with jQuery 1.8 or above, apparently). More examples can be found in the examples project in the form example module.

"Panels are great, but how do I change this one page?"

In a hurry to get this information up... Sorry for any typos :)

This module lets you take the input from a field and allows using HTML and token replacement (or alternately PHP) for display.

This is the module that is used on this site for code highlighting.

I just read a great article on this that breaks things down very well. You can find the original article here: http://fredparke.com/blog/create-your-own-tokens-drupal-7

Basically, you need to use two hooks. The first one tells the system about your token. The second one contains the specific logic for your token.

A nice way to add placeholders to input fields. "This module auto-converts form input fields with space-hogging labels into compact mobile-friendly input fields, with placeholders that animate into much smaller labels the moment text is keyed in. "

The gist: "This module extends the functionality of the core 'file' field, adding new capabilities to the file upload widget, and providing a new extendible field formatter for displaying lists of files."