An insider is someone, either an employee, or a third party adviser, who has access to non-public information that might affect our share price.
Directors of Stitch are automatically classed as insiders. Your role in the company may mean you also regularly handle non-public information or you may be involved in a special project which means that, for the length of the project, you are classified as an insider. Being included on a Price Sensitive project list is an example of this.
You can read the definition of an insider in the knowledge base.