Annotation is one option in ArcGIS for storing text to place on your maps. With annotation, each piece of text* stores its own position, text string, and display properties. Dynamic labels are the other primary option for storing text. If the exact position of each piece of text is important, then you should store your text as annotation. ArcGIS fully supports two types of annotation: geodatabase and map document. ArcGIS also supports the display and conversion of other annotation types including ArcInfo coverage and computer-aided design (CAD).
Labels are the main alternative to annotation. A label's text and position are generated dynamically according to a set of placement rules.
*Although annotation is mainly used to maintain the persistence of pieces of text placed on or around a map; both geodatabase annotation and map document annotation also support the storage of graphic shapes.
Making a map with annotation
The following steps provide a workflow that you can follow to use annotation in your maps.
- Add your existing annotation to ArcMap.
If you don't have annotation, you can label features in ArcMap and convert the labels to annotation.
If you have coverage, CAD, or other annotation formats and want your annotation to be editable or linked to features, convert them to geodatabase annotation using ArcToolbox.
- Change the symbology of your geodatabase annotation using ArcMap editing tools.Layer Properties dialog box. These changes are reflected on the current map only, unless you save them in a .lyr file. If you have map document annotation, use the Draw toolbar to change symbology.
- Use the ArcMap editing tools to position geodatabase annotation.Draw toolbar.
- Manage your geodatabase annotation with ArcCatalog.
Geodatabase annotation elements are stored in special types of feature classes inside the geodatabase. If you want editable text that you can use in many maps, you should store your text in geodatabase annotation feature classes. You can create geodatabase annotation feature classes in either ArcMap or ArcCatalog.
Storing annotation in a geodatabase is similar to storing geographic features—lines, points, and polygons—in a geodatabase. You can add annotation stored in a geodatabase to any map, and it appears as an annotation layer in the ArcMap table of contents.
Like other feature classes in a geodatabase, all features in an annotation feature class have a geographic location, extent, and attributes. Annotation feature classes can be inside a feature dataset, or they can be stand-alone feature classes in a geodatabase. However, annotation features differ from simple features in that each annotation feature has its own symbology.
Geodatabase annotation can be standard or feature linked. Standard annotation elements are pieces of geographically placed text that are not formally associated with features in the geodatabase. For example, you might have a piece of standard annotation that represents a mountain range—the annotation simply marks the general area on the map. Feature-linked annotation is a special type of geodatabase annotation that is directly linked to the features that are being annotated by a geodatabase relationship class.
Feature-linked geodatabase annotation
Feature-linked annotation is similar to standard geodatabase annotation but also has some properties that make it similar to dynamic labeling.
- When a new feature is created, new annotation is automatically created. You can turn this off when you create a feature-linked annotation feature class.
- If you move a feature, the annotation for that feature moves with it.
- If you edit a feature, the annotation for that feature will maintain its relationship with the feature. You can turn this off when you create a feature-linked annotation feature class.
- If you change an attribute of the feature on which the annotation text is based, the annotation text changes.
- If you delete the feature, the annotation is deleted.
An annotation class can be linked to only one feature class, but a feature class can have any number of linked annotation feature classes.
There are several ways to create feature-linked annotation. First, if you have defined a feature-linked annotation feature class, then as you create features using the editing tools in ArcMap, annotation is created for these features automatically.
Second, you can also use the Annotate selected features command in ArcMap to add linked annotation to existing features.
Finally, you can convert labels to feature-linked annotation in ArcMap or use the ArcToolbox annotation conversion tools to create feature-linked annotation from coverage or CAD annotation.
Map document annotation
Map document annotation is stored inside the map document (.mxd). If you have a relatively small amount of editable text, and that text will only be used in a single map, you should store your text as map document annotation. Map document annotation is best organized using annotation groups. You can create annotation groups in ArcMap by using the Draw toolbar.
Graphic text is useful for adding information on and around your map that exists in page space—as opposed to annotation, which is stored in geographic space. Dynamic text is a type of graphic text that, when placed on a map layout, will change dynamically based on the current properties of the map document, data frame, or Data Driven Page. If you want to place text information on your map page that does not move as you zoom and pan on your map, you should use graphic text. Graphic text can only be added to ArcMap in layout view.Learn more about dynamic text
All annotation stored in geodatabase annotation classes and most annotation stored in map annotation groups have a reference scale. Regardless of the map scale, text with a reference scale always takes up the same amount of geographic space on the map. The reference scale is a mechanism that allows you to specify a text size in page units (for example, points). The reference scale is simply the scale at which annotation text will appear on the page or screen at its symbol size.
For example, if you have an annotation group with a reference scale of 1:100,000 and it contains several pieces of 12-point text, when that text is displayed on a map of the same scale, the text on the page or screen will be exactly 12 points. At scales smaller than 1:100,000, the text will be smaller than 12 points on the page or screen, and at scales larger than 1:100,000, the text will be larger than 12 points.
Zero is a special value for an annotation group reference scale. Text with a reference scale of zero always appears at the same page size, regardless of the map scale. Therefore, if you have 12-point text stored in an annotation group with a reference scale of zero, the text will appear on your map at 12 points, regardless of the scale of the map.
- Setting a zero reference scale for an annotation group makes the annotation scale like dynamic labels (constant page size). This is useful when making interactive maps.
- To make your dynamic labels' size more like annotation (constant size in geographic space), set a reference scale for your data frame:
- Set the scale of the data frame to the scale you want to use as the reference scale.
- Right-click the data frame in the table of contents and click Reference Scale > Set Reference Scale.
- You cannot specify a zero reference scale for geodatabase annotation classes.
Other annotation types
ArcGIS also supports the display and conversion of several annotation formats including ArcInfo Workstation coverage, Vector Product Format (VPF), CAD, PC ARC/INFO, and SDE 3.x annotation. You can add these types of annotation directly to ArcMap and change most annotation layer symbology properties. For these formats, however, you cannot change the symbology for individual pieces of annotation, and you cannot edit the annotation positions or text strings. If you need these properties, convert your annotation to geodatabase annotation or map document annotation using the ArcToolbox annotation conversion tools. You can also use these tools to create coverage annotation from geodatabase annotation.