Added provider id section to modes

Author: schnuerle

modes/README.md

@@ -7,9 +7,10 @@ All MDS APIs should be mode-agnostic.
 ## Table of Contents
 
 - [Modes](#modes)
+  - [Provider ID](#provider-id)
 - [List of Supported Modes](#list-of-supported-modes)
 - [Mode Attributes](#mode-attributes)
-- [Unique Mode Properties](#unique-mode-properties)
+- [Mode Properties](#mode-properties)
 
 ## Modes
 
@@ -25,6 +26,12 @@ Each mode defined in MDS shall include key descriptive information, such as jour
 
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+### Provider ID
+
+MDS is intended to be used for multiple transportation modes, including its original micromobility (e-scooters, bikes, etc.) mode, as well as additional modes such as taxis, car share, and delivery bots. A given `provider_id` shall be associated with a single mobility [mode], so that the mode does not have to be specified in each data structure and API call. A provider implementing more than one mode shall [register](/README.md#providers-using-mds) a unique `provider_id` for each mode.
+
+[Top][toc]
+
 ## List of Supported Modes
 
 - **[Micromobility](/modes/micromobility.md)** (`micromobility`) - dockless or docked small devices such as e-scooters and bikes.
@@ -82,9 +89,9 @@ The `accessibility_options` array returns a list of JSON-formatted key/value pai
 
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-## Unique Mode Properties
+## Mode Properties
 
-While each mode is unique in its operational and business models, there are several areas where there are significant differences from one mode to the next. Each of these areas is defined in more detail within the mode, and each pull from a base of options defined in a global location.
+While each mode is unique in its operational and business models, there are several areas where there are significant differences from one mode to the next. Each of these areas is defined in more detail within the mode, and each pull from a base of options defined in a central location.
 
 ### Vehicle States