How Create Labels (Coverage) works

The Create Labels tool is often used to create label points for a coverage that has no polygon label points.

A few special cases of User-ID assignment using ID Base are listed below.

If the specified ID Base is negative, all new User-IDs generated by Create Labels will start with the specified value and be decremented by one for each new label point (for example, a value of -10 will result in User-IDs for new label points of -10, -11, -12, and so on).

Create Labels does not check whether the User-ID number to be assigned to a new label point already exists for a previous polygon label point. This could result in the generation of duplicate User-IDs, depending on the value specified. Duplicate User-IDs are allowed but not recommended. For example, existing attributes may be different for polygons that have the same User-ID.

Once Create Labels has been run on a coverage, the new label points and their User-IDs are stored in the LAB file. However, any previously existing User-IDs in the PAT of the coverage have not yet been updated. This creates a temporary situation where the new User-IDs generated by Create Labels are not equal to the old User-IDs stored in the coverage PAT.

You can use one of two methods to make the old User-IDs and the new User-IDs equal. One method is to use the Update IDs tool (IDEdit) to change the label point User-IDs to be equal to the User-IDs stored in the PAT. The second method is to use the Build tool to change the User-IDs stored in the PAT to be equal to the label point User-IDs. In other words, when different User-IDs are encountered, Build uses the new User-IDs in the LAB file to overwrite the old User-IDs in the PAT, whereas IDEdit uses the old User-IDs in the PAT to overwrite the new User-IDs in the LAB file. You must use whichever method is appropriate.

Several specific cases are described below:

6/18/2012