Terminology

Term	Description
Action (DE: Vorgang)	An "action" in the context of the KassenSichV is a related recording process of an electronic recording system. An action can comprise one or more business-actions as well as other procedures, occurrences and events. Each action must trigger at least one transaction logged by the certified technical safety device (DE: TSE). The term "action" is used as a generic term for "business-actions" and other actions to be secured.
Transaction (DE: Transaktion)	In the context of the logging of an action at least one transaction must be generated within the certified technical safety device (DE: TSE). While an "action" refers to the processes in the recording system, a "transaction" describes the safeguarding steps within the certified technical security device (at least at the beginning and end of the action) to the action in the respective recording system.
Business-action (DE: Geschäftsvorfall)	Business-actions are all legal and economic transactions that document, influence or change the profit or loss or the asset composition of an enterprise within a certain period of time.
Flow	The "flow" describes the communication between the POS-System and the fiskaltrust.Middleware to trigger transactions. This can be done either explicitly (each transaction has to be initiated "explicitly"; e.g. "Start" or "Finish") or implicitly (a "Start-Transaction" is done behind the scenes automatically - implicitly - upfront to the final call).
Abgabenordnung (AO)	A central German tax law that sets out the essential requirements for bookkeeping and thus also for cash management. TSE and cash audit are dealt with in Sections 146a and 146b, while Section 379 lists fines for violations.
Kassensicherungsverordnung (KassenSichV)	Cash Security Ordinance. The Abgabenordnung (AO) contains the basic regulations on the taxation procedure applicable to all types of taxes; the KassenSichV concretizes these general rules.
Application decree (DE: Anwendungserlass)	Instruction from a ministry to subordinate authorities on how to interpret and apply a particular law and its regulation.
GoBD	The Grundsätze zur ordnungsmäßigen Führung und Aufbewahrung von Büchern, Aufzeichnungen und Unterlagen in elektronischer Form (GoBD) are principles for the proper keeping and storage of books, records and documents in electronic form as well as for data access.
DSFinV-K	The Digitale Schnittstelle der Finanzverwaltung für Kassensysteme (DSFinV-K) is a German standardization of cash register records. It describes primarily the taxonomy for cash register data defined by DFKA e.V. The taxonomy maps the data by default in a JSON format. In addition, it provides a way to convert the data into a CSV structure (multiple interlinked tables). Since the tax authorities can only evaluate CSV data, DSFinV-K uses this representation.
Taxonomy	Always refers to the DFKA cash register data taxonomy. This taxonomy standardizes the individual records and daily financial statements of POS-Systems, irrespective of manufacturer and industry. It provides standardized data for POS-System inspections and audits and enables a uniform interface between POS-Systems and accounting.
Single record	The separate recording of each business transaction so its content can be traced. According to the German application decree for Section 146 AO, the following must be recorded: the designated item sold, the final retail price, the associated sales tax rate and amount, agreed price reductions, the method of payment, the date and time of the transaction, and the quantity or number sold.
POS-System	Electronic recording systems (also: electronic cash register, cash register system, input station, terminals, electronic or computer-based), meaning technical solutions specialized for the sale of goods or the provision of services and their settlement that have a cash register function. A cash register function means using POS-Systems to record and process at least partially cash payment transactions. It also applies to comparable electronic forms of payment used on-site (electronic money such as cash cards, virtual accounts or bonus point systems from third-party providers) as well as vouchers, credit cards, receipts and the like accepted in place of cash. A storage facility for the money managed (e.g., cash drawer) is not required. For example, cash register functions integrated into ERP or merchandise management systems fall within the definition of electronic recording systems. Not included are ticket vending machines, ticket printers, electronic accounting programs, vending and service machines, automated teller machines, taximeters and odometers, and cash and merchandise gambling devices.
POS-System inspections	Since January 1, 2018, the tax authorities can carry out unannounced checks on cash management outside of standard company audits. Before this, there were also individual POS-System inspections, which used the already existing instrument of the VAT inspection.
TSE	POS-Systems need a hardware-based or cloud-based TSE (Technische Sicherheitseinrichtung). A technical security device consists of a security module, a storage medium and a uniform digital interface. Only a TSE certified by the BSI (Federal Office for Information Security), which is responsible for the conception and certification, may be used.
TSE: Authenticity	The data actually originates from the alleged originator, e.g., the respective company.
TSE: Integrity	The data has remained unchanged since creation, and nobody removed records.
Unified digital interface	The term from § 146a AO was not clearly defined when the law was formulated. Three interfaces have emerged from it in practice: the export interface of the TSE (interface for data retrieval from the TSE), the integration interface of the TSE (interface for the communication of the cash register with the TSE, which is only a recommendation and thus not uniform due to the technology openness) and the DSFinV-K.
Certification	Confirming the successful compliance check with legally defined requirements. For the TSE, the BSI has published several technical guidelines and protection profiles. TSE manufacturers can have the compliance of their product with these requirements examined by a test center, which prepares an evaluation report. The BSI then issues certification based on this report.
Test value	In various regulations, this term is used instead of signature.
TAR	A data format to combine many files into one, the TAR file. The standardized data export of a TSE results in a TAR file.

Table 1. Key terms used in the German KassenSichV context.