# Material categories - [Processed Glass](https://docs.buildingtransparency.org/ec3/material-categories/processed-glass.md): This page provides additional descriptions on the different types of processed glass included in the EC3 database so that users can ensure they find EPDs that are appropriate for their needs. - [Painting & Coating](https://docs.buildingtransparency.org/ec3/material-categories/painting-and-coating.md): This page provides additional descriptions of the paint category in the EC3 database to help users understand how EPD results are defined, reported, and compared. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.buildingtransparency.org/ec3/material-categories.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.