To what sources of spatial data does the NSDI Act refer to?

The NSDI Act in accordance with Art. 6. applies to spatial data sources under the condition that:

they refer to the territory of the Republic of Croatia, internal sea waters, territorial sea, continental shelf and its ecological protection or economic areas and other areas over which the Republic of Croatia exercises sovereign rights,
they are in electronic form,
they are within the jurisdiction or scope of NSDI subjects,
they refer to one or more themes from Article 9, Paragraph 1 of this Act,
they do not refer to classified spatial data.

A list of all themes along with their descriptions is available via the link.