What a tag is
A tag is a reusable label you attach to activities. Facilities, business units, regions, suppliers and fuel codes are all tags. Tags are how you group, filter and report on your emissions.
Every tag has three fields:
Field | Required | Description | Example |
type | Yes | The kind of tag |
|
name | Yes | The tag's identifier. This is what you use to reference the tag anywhere else. |
|
title | No | The display name shown in the app | Denver - Office |
A tag is identified by its type and name together. That means site-a can exist both as a facility tag and as a business_unit tag without conflict.
What a trait is
A trait is a piece of information stored on a tag. For example, a facility tag might carry these traits:
country: USstreet_address: 1200 Main Stfacility_type: Officeus_egrid: RMPA
Traits pass down to every activity that carries the tag. If ten activities are tagged with denver-office, all ten inherit country: US automatically. This is why you only need to enter a facility's location once.
Tags and traits behave the same way
For grouping, filtering, reporting and automatic emission factor assignment, Measure treats a trait the same as a tag placed directly on the activity. The difference is only where the information is attached:
A tag attaches directly to an activity, and can carry its own traits.
A trait attaches to a tag, and cannot carry traits of its own.
Choosing between a tag and a trait
Ask two questions:
Do you need to tell apart activities that share the same tag? A trait applies to every activity under a tag equally. If two activities at the same facility need different values (for example, one runs on diesel and one on propane), that value cannot live on the facility tag as a trait, and must be its own tag on the activity.
Does the thing need details of its own? If you want to store extra information about it, it must be a tag, because traits can't have traits.
If the answer to both is no, use a trait on the existing tag. If either is yes, create a separate tag.
Example
A company wants to report by region. Each facility belongs to exactly one region, and regions don't need any extra details. Storing region as a trait on each facility tag works well.
Later, the company wants to record a regional manager and a regional target for each region. Now regions need their own details, so region should become a tag with its own traits.
Controlled tag types
Some tag types use a fixed list of values maintained by Measure, for example country, fuel_code, vehicle_code, gas, naics_code, material, disposal_method, us_egrid, ca_province, au_state and chilled_water_system. Measure already knows these values and shows their display names for you, so you don't need to create them or give them titles.