RTE snippet is used when you have to write same html again and again or have some content that look the same but maybe with difference in text in RTE, you should consider making a snippet.
You need to follow some steps for creating RTE Snippet –
1) Switch to core database
At the bottok2m right of your screen there is a database icon, click this to open the context menu and select core.
2) Go to Snippet under settings node
Once switched to core database browse the following node
(sitecore/system/settings/Html Editor Profiles/Rich Text Default/Snippets)
3) Insert a new snippet
You can either duplicate a snippet that already exists or add a new one.
To add a new snippet right click to Snippet folder
And create a snippet using the following template:
/sitecore/templates/System/Html Editor Profiles/Html Editor Snippet
This template consists of two fields, a header field and a value field.
a) In the header field you can write the name that is the title of snippet.
Snippet is created now, now you can use it. Don’t forget to switch to master database.
How to use Snippet –
Go to the item that has Rich Text Editor (RTE) type field. Then click to “Show Editor”.
When you press the “Insert Code Snippet” button you will see the new snippet that you have just created. Then you can use it by clicking that snippet.