The current standard is Part 1. There are likely to be other parts that could further address, for example:

• A particular sector of the economy, such as legal writing and drafting.
• Further details on plain language practices, such as information design.

There may be more parts that are suggested over time. 

Countries may also localize the standard, which means translating or adjusting the standard for a specific country. It can also mean making additions to the standard to reflect local needs. For example, a country may want to add more detailed aspects of a specific language, such as grammar preferences that improve clarity. In English, examples of this are preferring the active voice to the passive voice and preferring verbs to nouns.