This service definitions and the implementation are limited to the provision of pre-defined data sets, as specified in the Annex 15 and PANS-AIM. This shall be seen as a minimal digital AIS data provision service. More advanced digital data services are also expected to be deployed by AIS, for example providing access to feature level data, for example in the form of a Web Feature Service (WFS). Such services will be subject to separate service definitions/descriptions and are not included here. An example of the capabilities expected from such services is provided in the OGC Web Feature Service (WFS) Temporality Extension Discussion Paper.