Systems require an interoperable way to store portrayal information so that information can be rendered consistently. There are a number of architectures where portrayal information needs to be shared. The Portrayal DWG has identified a particular need to store portrayal information in the GeoPackage so that it is available along with the data and accessible in off-line scenarios. The candidate extension has undergone a number of revisions. In the latest version, used by Testbed-16 participants, five new tables are created. One contains style names and URIs. One contains stylesheets, so that a single style may be represented by multiple encodings. One contains symbol names and URIs. One contains symbol images, so that multiple images may be grouped into a sprite file. One contains symbol content, so that a single symbol may be represented by multiple encodings.

There is a common pattern where it is useful to annotate any business object (layer, feature, tile, style, etc.) with a resolvable URI. One scenario where this pattern occurs is stylable layer sets which aggregate groups of styles that are designed to be used together. add more scenarios…​

Conventional features have proven to be inefficient when visualization is the top priority. Through the work of the OGC Vector Tiles Pilot Phase 1 and Phase 2, tiled feature data has proven to be a robust, more efficient solution. Support of tiled feature data in GeoPackage would create a way for GeoPackage clients to leverage the superior efficiency in a way that is consistent with other emerging uses in the OGC baseline (e.g., OGC API - Tiles). In the Pilot, four extensions were proposed. The first extension declares that vector tiles are in use and establishes two new tables for tiles metadata. The second and third extensions declare that tiles may be in the Mapbox Vector Tiles and GeoJSON formats, respectively. The fourth establishes a mechanism for encoding feature attribute information in a relational way so that it can be queried more easily. These extensions would be published as part of the same document.

The tiling supported by the GeoPackage core is simplistic and does not support all of the options provided by the OGC Tile Matrix Set Standard (OGC 17-083r2). An extension developed in Vector Tiles Pilot Phase 2 (see above) is a candidate for meeting this need. In the candidate extension, four new tables are added that align to the conceptual model from 17-083r2. The existing tiles tables would be replaced with views that reflect the content of the new tables. In addition, triggers would allow reverse compatibility by redirecting insert, update, and delete statements on the views to the relevant tables.

This extension would replace the existing Zoom Other Intervals extension (Annex F.6).

There is the work that is being done on the next version of CDB to support 3D models. However, this capability is desirable in GeoPackage because some users may want to avoid the burden of CDB. Candidate technologies include 3D tiles and glTF.