> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/ios/layers-ocgs.md). # Layers (OCGs) - [PDF Layers (OCGs) on iOS](https://docs.apryse.com/ios/layers-ocgs/layers.md): Learn how to show/hide, add, and extract layers in a PDF document. Optimize your PDF viewing experience with these simple steps. The Apryse iOS SDK streamlines secure document processing and seamlessl - [Show or hide PDF layers on iOS](https://docs.apryse.com/ios/layers-ocgs/ocg-layer-browser-i.md): Explore the functionality of PDF OCG (Optional Content Groups) dictionary with PTPDFLayerViewController. Render and control layers in your PDF documents easily. Learn how to use this feature efficient - [Add a new PDF Layer on iOS](https://docs.apryse.com/ios/layers-ocgs/add-layer.md): Learn how to add a PDF layer or OCG (optional content group) to a new document with full sample code for creating, extracting, and rendering PDF layers. Master PDF layer manipulation now! The Apryse i - [Extract layers from PDF on iOS](https://docs.apryse.com/ios/layers-ocgs/extract-layer.md): Learn how to extract PDF layers or OCG (optional content group) from a document with full sample code. Create, extract, and render PDF layers effortlessly. The Apryse iOS SDK streamlines secure docume - [Code samples for working with PDF Layers on iOS](https://docs.apryse.com/ios/layers-ocgs/samples.md): Discover how to create PDF layers (OCGs) with this sample. Learn about Optional Content Groups and enhance your PDF files. The Apryse iOS SDK streamlines secure document processing and seamlessly inte - [APIs for PDF layers (OCGs) on iOS](https://docs.apryse.com/ios/layers-ocgs/apis.md): Discover utility classes for layers (OCGs) in PDF documents with iOS (Objective-C/Swift) PTGroup. Enhance your PDF functionalities today! The Apryse iOS SDK streamlines secure document processing and --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.apryse.com/ios/layers-ocgs.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. 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.