We recommend that you get thoroughly acquainted with the standard because the following requires advanced know-how of the RDS 81346 standard. The "A Guide to RDS - Reference Designation Systems" handbook contains more detailed information.
Syntax Element
When classifying any system or system element, you may, according to the rules in RDS 81346 use one, two or three-letter codes as a part of the reference designation. But to be practical, it has turned out to be very useful to use:
ONE letter code (Main systems) for designation of high-level systems, i.e., high abstraction level.
TWO letter code (Technical systems) for designation of mid-level systems, i.e., mid abstraction level.
THREE letter code (Component systems) for designation of component systems, i.e., low abstraction level.
This means that the syntax elements represent the abstraction levels of TAG systems. See the syntax elements you build as either your high-level systems, mid-level systems, or component systems.
Below you will find information on everything the syntax element contains. This will help you create a proper syntax element.
Add the Syntax Element
To create a syntax element you press the "add" button and the window below will unfold. Start by naming the syntax element.
Aspects
Different filters called aspects are used to view a context. The aspects constitute a well-defined method by which to select and present information.
By applying an aspect, you can only see the information relevant for this aspect (Functional, Product, Location and Type).
We strongly advise you to keep information separated, which means that you should not mix the aspects, but keep them apart.
There is a strong correlation between aspect and context: No context without an aspect and vice versa.
The aspects "sharpen the world" by leaving out the information you do not need.
An aspect is a particular "filter" for the information you are working with. The figure below illustrates the four basic aspects from 81346-1, which will indicate how to view a context.
As illustrated in the figure, there are four basic aspects:
Product aspect (-)
Type aspect (%)
Function aspect (=)
Location aspect (+)
Numbering Range
The numbering range dictates how many systems you can create within that syntax element. You have the ability to, e.g., limit the range from 1-9, but we recommend that you choose 1..-∞, so you can create as many systems as you need in your structure.
Classification Table
Depth
The depth of a syntax element dictates a specific syntax element's nesting level. It governs whether a syntax element can be applied on the 1st, 2nd, 3rd, or infinite levels on the tree structure.
As a rule of thumb, a high-level systems syntax element would normally have a depth of 1,2, which means that there can be a high-level system in a high-level system as illustrated below (the one-letter code defines the high-level system):
The same goes with two-letter codes (mid-level systems). On the other hand, component systems would typically be nested on an infinite level because the abstraction level is low. Practically that means you can build endless component systems on each other.