"Labels are text blocks or symbols optionally linked to construction elements and 2D fills. Labels allow you to identify or comment elements or parts of your design." That's from the Archicad 9 Ref Guide page 343, and it's pretty succinct so I'll keep it. Here's more:
"You can use labels in two ways:
• Independent labels manually placed using the Label tool.
• Associative labels can be assigned automatically before the creation of an element or added to them later."
So there's two kinds. Independent labels are like regular objects, in that they do their own thing. There is a simple text label that's basically a text block with a leader, and it works OK as long as you don't go longer than one line. I (used to!) use these to call out structure in the sections and other simple things like that. They are a marginal improvement over plain text with an arc.
Associative labels are attached to elements, and can say intelligent things about them. They remain accurate as the data they represent changes. They can move when the element is moved. They are very cool.
(Why don't we use them yet? Because the underlying design of the label functionality is very poor, making it hard to figure out how they work, especially the differences between the two kinds. Now that I/we have them figured out, the actual making isn't hard.)
Frequently (Probably) Asked Questions follow. I'm focusing on associated labels, since independent labels are simple.
Q What are labels?
A They are objects, which means they are written in GDL, like doors and windows, etc. They live in the libraries. Unlike objects, lamps, doors, and windows, you don't select them in that browser-looking window in the settings. Instead, labels are like Details, Sections, and Zone Stamps, where Archicad puts all the loaded labels together in one list, on a flyout in the info box or settings dialog. I don't know why they think this is better.
Q How do I place an associated label?
A A couple different ways. In the ID tile of the info box, there's checkbox that says "Label Elements". (There's a similar checkbox in the Listing and Labeling panel of the settings dialog.) If this box is checked in the default settings, the elements will label themselves automatically when they are placed. If you check this box for a placed, selected element, the label will appear.
Q Is the element labeled everywhere, automatically? For example, in the sections?
A No. The status of the checkbox is independent in each view of the element. Even though the element is labeled in the plan, when you go to the section, it won't be, and the box is unchecked. Check the box, and the label appears.
Q I have to do that in each section?
A Yes.
Q That's not ideal.
A No, but it's still easier than placing text, or text label. But the real payoff is that the labels in all the sections will update automatically if the element data changes, and the label will follow the element if it changes location.
Q Any other glitches?
A You can only label elements in plan on their home story. I think this stinks, but we'll survive, since object (and door and window) labeling can be handled in the regular 2D symbol anyway.
A (I think) You can't control where on the element the label pops up, although you can move around all you want, and it doesn't even have to touch the element.
Q There's another way to place an associated label?
A Yes, you can place them using the label tool, if the Associated method is on. In the info box, this little flyout is next to the label list flyout. Placing a label this way is the same as selecting the element and checking the box. This way you can at least pick the reference point, if not the text location.
Q How do you delete associated labels?
A Select them and delete them, or select the element and uncheck the box. This only affects the label in the current window. If a labeled element is deleted, all its labels go to, in all windows.
Q Why can't we label Zones in section?
A Beats me.
Q That would be great.
A Sure.
Q Hey, zones are 3D, and they don't show up in section at all! What's the deal?
A I feel your pain.
Q OK, the labels. How do you set them up before they go and start placing themselves?
A Two ways.
In each tool's settings, in the Listing and Labeling panel, the Label Settings button will open a Label tool settings dialog, where you can set up the label. These settings will be used for any subsequent associated label for that tool's elements, whether placed on the fly or after the fact.
In the Label settings dialog (Label tool active, Cmd+T), with the Associated method on, all the labelable (spellcheck!) tools appear in the top panel. You can highlight each one and set up all the default labels for the different tools.
Q So, what labels should we use?
A I have a few, which I'll describe. The big idea I want you to get is that labels can say virtually anything about any element, automatically, dynamically. We are at the edge of a new territory. I would like to hear your ideas about what needs to be smart labeled.
The current line up:
Roof Slope JAM9 looks just like Slope Symbol JAM8, except it learns the slope from the roof.
Wall Height JAM9 gives the height of a wall untrimmed, or maximum/minimum as trimmed. Helps with knee walls!
Description JAM9 expresses any text parameter of any object. Its original intent is labeling structure in section, but they can be used for anything.
Q Are labels hard to make?
A They are incredibly easy, considering how tough it was to figure them out, and considering how powerful they are. It's a topic for another post, though.