This is taken from the extension site:

MosSnippet is a plugin (mambot) to insert text, html or php code in content. Now you don't have to worry about the wysiwig editor sabotaging your precious code! You can create up to 30 snippets using the fields in the mambot editor. You insert the snippets in content by referring to the number or an optional name. For example, {snippet 1} or {snippet paypal}. When processed, the tags will be replaced with the snippet in question. Text and html code will be inserted unaltered, while php code will be interpreted. EXAMPLES TEXT OR HTML Just paste the text/code into the snippet field. It will be inserted exactly like entered. Example: Click here PHP You must enclose the code with tags. Just like ordinary PHP code. You can use the MIX You can mix everything if you just remember the appropiate opening and closing tags. You can have as many blocks of html and php as you like. Example: MosSnippet MosSnippet is a great plugin for inserting html and php in content! LINKING EXTERNAL FILES This is done using straight php ... �