Parcels are added to the parcel fabric as parcel types. A parcel type is composed of a polygon and line feature class and is defined by your organization. For example, your organization may manage both ownership/tax parcels and subdivision parcels. You can add as many parcel types as necessary for your organization.
Use the Add Parcel Type geoprocessing tool to add a parcel type to your parcel fabric. Right-click a parcel fabric in the Catalog pane, point to Manage and click Add Parcel Type 
to load the Add Parcel Type geoprocessing tool.
The tool adds creates a polygon and line feature class and adds the parcel type feature classes to the geodatabase topology.
Parcel types work as follows:
- Both the parcel type polygon and the line feature are associated with the parcel record.
- Parcel data is loaded into the parcel fabric by appending parcel features to the parcel type feature classes.
- Parcels are z-aware and can be visualized in both 2D and 3D.
Parcel types can have their own behavior, which is defined by schema (attribute fields and related tables) and a combination of geodatabase topology rules and attribute rules. For example, rules can be configured to allow certain parcel types to overlap and other parcel types to not overlap.
Use the Remove Parcel Type geoprocessing tool to unregister a parcel type from the parcel fabric. The parcel type feature classes can be deleted.
Boundaries
A single shared line is used to represent adjacent parcel boundaries when the following conditions are met:
- The adjacent boundaries have matching dimensions and lie between the same points.
- The adjacent boundaries belong to the same parcel type.
Overlapping lines are used in the following circumstances:
- The adjacent, coincident boundaries show different dimensions.
- The adjacent boundaries do not lie between the same points, for example, a right-of-way boundary line that is adjacent to a series of parcels.
- The adjacent boundaries belong to different parcel types.
Parcel lines are associated with the record that created them. The Created By Record field of a parcel line is populated with the GlobalID of the associated record from the Records table.
When merging, splitting, or constructing parcels, if parcel line dimensions are unchanged from their original parcel record, the lines remain associated with their original parcel record. Parcel lines remain associated with the record that originally created them until a newer parcel record redefines the dimensions of the line (changes the line). This can result in parcel polygons being defined by lines that are associated with different records. This allows you to identify changes in a parcel record and to track line history by recorded dates.
Administrative boundaries
Parcel types can use administrative boundaries. Administrative boundaries are used for very large parcels such as country parcels or state parcels. To add a parcel type that uses administrative boundaries, choose Use for administrative boundaries on the Add Parcel Type geoprocessing tool.
If a parcel type uses administrative boundaries, the parcel type polygon feature class is excluded from the geodatabase topology.
Parcel seeds
When building parcels from lines, parcel seeds are used. A parcel seed is the initial state, or seed state, of a parcel. A parcel seed indicates to the build process that a parcel should be built from the lines enclosing a seed.
Parcel seeds are represented as small polygons and have the same schema as their parcel types. Parcel seeds can be automatically generated for a network of lines in which seeds are created in all closed loop sequences of lines.