There are four German-specific capacity categories, which can be found on the PRISMA Platform.
1. FZK (Frei Zuordenbare Kapazität, literally Freely Allocable Capacity): This term denotes firm capacity accessible at Virtual Trading Point in the Entry-/ Exit-System. No conditions apply to the use of FZK capacity.
2. bFZK (beschränkt Frei Zuordenbare Kapazität, literally Conditionally Freely Allocable Capacity): In general, this capacity is also freely allocable and accessible at VTPs. However, the access to VTPs is subject to predefined conditions, e.g. temperature and pressure. If the conditions are not met, the corresponding Entry- or Exit-Points are limited -- that is, a specific Entry-Point can only reach a specified Exit-Point. Otherwise, the capacity might be interrupted.
3. DZK (Dynamisch Zuordenbare Kapazitäten, literally Dynamically Allocable Capacity): This capacity type allows only for restricted access to the VTP. On a firm basis, only predefined (Exit) Points can be reached with the assigned (Entry) Capacity. Otherwise, the VTP is not reached on a firm basis. If not assigned to a specific point, the VTP is accessible on an interruptible basis only.
4. BZK (Beschränkt Zuordenbare Kapazität, literally Restricted Allocable Capacity): In this case, the transportation is only allowed from a dedicated Entry-Point to a pre-defined Exit-Point. They are not allowed at VTPs.
Please be aware, that there is an ongoing BNetzA consultation (see: https://www.bundesnetzagentur.de/DE/Service-Funktionen/Beschlusskammern/1_GZ/BK7-GZ/2018/2018-0001bis0999/2018_0001bis0099/BK7-18-0052/BK7-18-0052_Verfahrenseinleitung.html ). It is, therefore, possible that BZK might not be offered in the future, should BNetzA decide as indicated.
In the audit documentation of BNetzA, you may also find a definition of these capacity types. It might help understanding: