Updated for Joomla 2.5
The instructions for TinyMCE as it appears with Joomla 2.5 are for the most part very similar to the Joomla 1.5 instructions. There is no longer a Code Cleanup setting, and some of the Advanced settings are different as well, but you can follow the instructions listed below. Just make sure that Entity Encoding is set to raw, and your Prohibited Elements aren't stripping out what you're trying to include, such as iframes.
Here's a screen shot of the newer version:
- Login to Administrator
- Go to Extensions - Plugin Manager
- Find the plugin called Editor - Tiny MCE and click its title to go into Edit mode
- Have a look at the parameters on the right hand side and make sure Code Cleanup on Startup is set to Off, change Code cleanup on save to Never and make sure Entity Encoding is set to raw (see image below). Further down, ensure that there are no desired tags in Prohibited Elements.
- Save using the button in the top right
When you next write or edit an article, click the HTML button in the editor and insert your HTML code. When you save the article, the HTML code you inserted will be preserved.