> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/products/maps-and-imagery-portfolio/os-mastermap-topography-layer/os-mastermap-topography-layer-technical-specification/feature-lifecycles-and-tracking-change/general-point-feature-lifecycle-rules.md). # General point feature lifecycle rules The lifecycles of point features are simpler than those of lines or polygons since they cannot change in size or be split into multiple features. ## **Creation of point features** When a new real-world object comes into being, a new point feature is created to represent it. If, however, the object is a replacement for a previous real-world object in the same position, the original feature is retained. An example would be if an existing post box was replaced by another post box in the same location. ## **Deletion of point features** When a real-world object is no longer present in the real world, the point feature is removed from Ordnance Survey’s holding. Ordnance Survey keeps a record to indicate that the feature with this TOID used to exist and notifies the user at the next date of COU supply. ## **Modification of point features due to real-world change** By the nature of the real-world objects represented as point features in OS MasterMap Topography Layer data, it is unlikely that one will be modified without changing its identity. Therefore, any modification to a point feature as a result of real-world change will result in the deletion of the original feature and creation of a new feature, unless there is a clear reason to identify the resultant real-world object with the original. This applies to both geometric change and change of descriptive group or descriptive term. ## **Modification of point features due to error correction** When a point feature is found to be incorrectly attributed due to an error or is moved due to the correction of a positional accuracy error, the original feature is retained and appropriately modified. This section has explained in some detail the lifecycles of features so that users can understand how the data is managed by Ordnance Survey. --- # 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.os.uk/os-downloads/products/maps-and-imagery-portfolio/os-mastermap-topography-layer/os-mastermap-topography-layer-technical-specification/feature-lifecycles-and-tracking-change/general-point-feature-lifecycle-rules.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.