Naming and typing of terms

Naming of terms

ACRIS Data Dictionary terms should follow the following rules for naming. 

• Only descriptive names should be used. It should be possible to understand what the term means without being an aviation expert.
• All term names are written with PascalCase, starting with an uppercase letter.
  The exception to this rule are XML defined data types like "dateTime" or "time" that are written as specified by XML specifications.
• Abbreviations like "UTC" are written as "Utc". See for example DateTimeUtc.
• When relating a term to an arrival or a departure prefixing of Arrival/Departure shall be used, ref. ArrivalGateId, DepartureGateId.
• No/very few abbreviations should be used. In some cases common abbreviations can be used. Allowed abbreviations are:
  • "Id": Identifier
  • The list will/might be expanded.
• When using terms that can be both an attribute and a data type then the recommendation is:
  • Use lower case for the first letter for the attribute.
  • The type is written as defined in the ACRISDD.
    Example: flightId : FlightId

Typing of terms

Terms that can be an attribute always have a type definition. The type is defined as an XML type as mapping from XML to other type systems are widely available.
The following rules apply to typing of terms:

• All terms that can be an attribute has one type associated.
• The type definition should be strict and work for strictly typed languages like Java.
• Dynamic typing where something can have multiple types depending on something else is not allowed.
  For instance, if an attribute defines the weight of something the type can't be either kilo or pounds depending on something. Only one type is allowed.
• For convenience XML types are used. Mapping from XML to other type systems are available.

Relationship to other standards

Consistency within the ACI Data Dictionary is important and shall be carefully considered when defining terms. The ACI Data Dictionary is a standard in a domain (aviation) where there already are multiple standards such as IATA (AIDM, AIDX, IATA Manuals, ...), ICAO, Eurocontrol (AIRM, FIXM). Some of these standards define terminologies that are used throughout the industry like Eurocontrol's A-CDM terminology defined in THE MANUAL. In cases like this it might be considered more important to adhere to the terminology of the existing standard than to have very strict internal consistency in the ACI Data Dictionary. 
Whether internal consistency or reuse of existing terminology is most important is considered case by case.

When terms from established standards are re-used or taken over 1:1, the sources shall be properly attributed.

Language to use

US English should be used for terms and descriptions.

Apart from European organisations most international publications seem to be in US English such as the examples listed below from ICAO, IATA, ACI World. The interaction with ANSP/ATM is a specific one, mostly in that particular domain whereas Eurocontrol is even a Europe specific one. IATA on the other hand covers a broader set of domains such as ACFT, PAX, BAG, CARGO, etc. and therefore seems more dominant from an airport integration point of view. Also multiple airport partners operate in these domains which make it appear reasonable to use the same type of English prevalent in these domains.

Page status: Approved 2024-05-03