AT&T MICHIGAN GUIDEBOOK

PART 1 - Preface and Table of Contents 6th Revised Sheet 1 SECTION 1 - Title Sheet and Symbols

TITLE SHEET

Regulations, Rates and Charges for the provision of the following Unregulated Services:

• Local Telephone Exchange Services - applying in the Exchanges and Zones of the Company in Michigan

• Auxiliary Services - applying in the Exchanges of the Company in Michigan

• Message Toll Services - applying to Intrastate Service in Michigan

• Directory Assistance Related Services - applying to Intrastate Service in Michigan

The Michigan Bell Telephone Company offers services under this guidebook. Michigan Bell Telephone (C) Company is also known as AT&T Michigan, SBC Michigan, SBC Ameritech Michigan, AT&T Wholesale and Ameritech Michigan. Services offered pursuant to this guidebook may be offered under any of these names or under the brand name AT&T or SBC. All unregulated services offered by Michigan Bell Telephone Company, whether under that name, the names AT&T Michigan, SBC Michigan, SBC Ameritech Michigan, AT&T Wholesale or Ameritech Michigan or under the brand name AT&T or SBC, are subject to the terms and conditions of this guidebook. Michigan Bell Telephone Company will hereinafter be referred to as "the Company" or "Company".

ATT TN MU-21-0016 Effective: February 28, 2021 AT&T MICHIGAN GUIDEBOOK

PART 1 - Preface and Table of Contents 5th Revised Sheet 2 SECTION 1 - Title Sheet and Symbols

EXPLANATION OF GUIDEBOOK CHANGE SYMBOLS

SYMBOL EXPLANATION

(C) Signifies a changed term/condition, or a change in text

(D) Signifies a discontinued rate, treatment, or term/condition

(I) Signifies an increased rate, or new treatment resulting in an increased rate

(M) Signifies moved material

(N) Signifies a new rate, treatment, or term/condition

(R) Signifies a reduced rate, or new treatment resulting in a reduced rate

TRADEMARKS AND SERVICE MARKS (N)

Telcordia® and Common Language® are registered trademarks and iconectiv, CLCI, CLEI, CLFI, CLLI, USOC, FID, NC, NCI and NC/NCI, are trademarks of Telcordia Technologies, Inc. The Common Language codes identified herein are the proprietary information of Telcordia Technologies, Inc. d/b/a iconectiv ("iconectiv") and are licensed to AT&T Services, Inc. The Common Language codes provided herein, if applicable, are solely for the purpose of this Guidebook and may not be reproduced, stored or used for any other purpose without the express, written consent of iconectiv. (N)

ATT TN MU-14-0054 Effective: October 1, 2014