Paired data is a group of data that represents a two variable relationship. Typical examples are data that make up a curve (e.g., a rating table or a flow-frequency curve). Several curves may be stored in the same record if one of the variables is the same. For example several frequency-damage curves may be stored in the same record, where the curves may be residential, commercial, etc. A scale associated with the variable may be one of three types: linear, logarithmic, or probability.  Some older files have a type 'UNT' (Unitary), which is consistent with linear.

An example of a pathname for paired data is:
/ALLEGHENY/NATRONA/ELEV-DAMAGE//2020/FLOOD PROOF PLAN B/

The pathname part identifiers are as follows:

Part A – Group

Part A for paired data is used as a way to group records. Usually this information is a watershed name, study name, project, river, or basin name; a name that allows the user to group associated records.

Part B – Location

Part B is the basic location identification of the paired data and could be a control point, damage reach ID, station ID, or other identifier.

Part C – Parameters

Because paired data represents a relationship between two parameters, Part C should contain the two parameter names separated by a hyphen '-'. Examples of parameters are:
ELEV-DAMAGE'
ELEV-FLOW
FREQ-FLOW
STATION-ELEV
In the above examples, ELEV, FREQ, and STATION are referred to as the first, independent variable while DAMAGE, FLOW and ELEV are the second, dependent variable.

Part D - Optional Descriptor

Part D of the pathname is used to provide any further descriptions of the data. Part D may vary from application to application as appropriate, and is often null.

Part E - Time Descriptor

Part E of the pathname is used only if the paired data is representative of a specific point in time.

Part F - General Descriptor

This part identifies a unique descriptor of the data such as the situation, condition, or alternative plan name associated with the data. This part is included in labeling of data in some output utilities.