From GRFSpecs

Object labels

Defining Object Class Label Recommendations

Recommendations - Predefined

1. Predefined labels are best used for single objects that are not part of a comprehensive set
2. It is possible to have a label for each object. This would make for a very ungainly menu.
3. A labeling system allows a coder/author to make their works much more user friendly.
4. To keep the numbers more manageable, the classes are as generic as possible.
5. While being generic, assigning objects to a label should be intuitive.
6. Assuming that there will be special circumstances where a coder/author needs to deviate from the norm, the Recommendation is not mandatory.

PREDEFINED RECOMMENDATIONS
Label	Action4 Text	Description
STRU	Structures	Multitile engineered objects that don't quite fit in as industries, houses or stations - dams etc.
INFR	Infrastructure	light poles, communication towers, transmission towers, road signs, etc.
BLDG	Buildings	Normally accommodated by industries, houses or stations but the author feels there are limiting circumstances.
NATR	Natural objects	caves, coral reefs, swamps, etc.
PARK	Public areas	Normally accommodated by towns or industries (tourist stuff ...) but the author feels there are limiting circumstances - Parks, statues, etc.
ARTF	Artifacts	They really don't fit under any of the above - shipwrecks, etc.
MISC	Miscellaneous	For the author who is unable to accommodate his/her object under any of the previous labels.

Recommendations - Author defined

1. Author defined labels are best used for comprehensive object sets that consist of several obviously related objects.
2. Each label must consist of four (4) alphanumeric characters.
3. To prevent menu confusion, new labels should be unique and should not duplicate predefined labels (see chart above) nor previously selected author defined labels (see chart below).
4. The author should add their label(s) to the following chart in alphanumeric order.
5. If an author is uncomfortable with adding a label to the chart, they can PM their request to wallyweb.
6. The chart will be regularly reviewed for duplications.
7. The chart will be regularly edited for alphanumeric sequence.

AUTHOR DEFINED RECOMMENDATIONS
Label	Action4 Text	Description	Author	TT-Forums link
EXM1	Example 1	An example label listing	your name here	Forum link goes here
NLRA	Dutch Road Furniture: Matrix Activators	Activators for matrix signs for Dutch Road Furniture	FooBar	http://www.tt-forums.net/viewtopic.php?t=56316
NLRF	Dutch Road Furniture	For Dutch road related objects (generic label)	FooBar	http://www.tt-forums.net/viewtopic.php?t=56316
NLRM	Dutch Road Furniture: Motorways	Motorway related objects for Dutch Road Furniture	FooBar	http://www.tt-forums.net/viewtopic.php?t=56316
NLRS	Dutch Road Furniture: Signs and Fingerposts	Road signs and fingerposts for Dutch Road Furniture	FooBar	http://www.tt-forums.net/viewtopic.php?t=56316