Easy read should use plain english. It should use words that you would find in everyday speech.
An easy read document may be read out to the person with learning disabilities - so you should use words that sound good if it is read out aloud.
Sentences should be short. Don't join sentences together to make longer sentences.
You should not use abbreviations and jargon unless you have to.
With abbreviations, you should always explain what the letters stand for.
If the letters of the abbreviation stand for complex words - then you should explain the abbreviation in easy words.
If you have to use jargon or other complicated words. You should explain what they mean in easy words.
The standard way is to put the jargon word in bold and then have a box which explains the complex word. We like the explanation to be on the same page as where the jargon word appears.
We don't like glossaries at the end of the document.