Sec Form 4 Filing - Carlyle Group Management L.L.C. @ CoreSite Realty Corp - 2019-08-07

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Carlyle Group Management L.L.C. 2. Issuer Name and Ticker or Trading Symbol CoreSite Realty Corp [ COR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O THE CARLYLE GROUP,, 1001 PENNSYLVANIA AVE., N.W. SUITE 220 S 3. Date of Earliest Transaction (MM/DD/YY) 08/07/2019 (Street) WASHINGTON, DC20004-2505 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 08/07/2019 M 800,000 A 800,000 I See footnotes ( 2 ) ( 3 ) ( 4 ) Common Stock 08/07/2019 S 800,000 D $ 110.74 0 I See footnotes ( 2 ) ( 3 ) ( 4 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Operating Partnership Units ( 1 ) 08/07/2019 M 800,000 ( 1 ) ( 1 ) Common Stock 800,000 ( 1 ) 10,725,390 I See footnotes ( 2 ) ( 3 ) ( 4 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Carlyle Group Management L.L.C. C/O THE CARLYLE GROUP, 1001 PENNSYLVANIA AVE., N.W. SUITE 220 S WASHINGTON, DC20004-2505 X Carlyle Group L.P. C/O THE CARLYLE GROUP, 1001 PENNSYLVANIA AVE., N.W. SUITE 220 S WASHINGTON, DC20004-2505 X Carlyle Holdings I GP Inc. C/O THE CARLYLE GROUP, 1001 PENNSYLVANIA AVE., N.W. SUITE 220 S WASHINGTON, DC20004-2505 X Carlyle Holdings I GP Sub L.L.C. C/O THE CARLYLE GROUP, 1001 PENNSYLVANIA AVE., N.W. SUITE 220 S WASHINGTON, DC20004-2505 X Carlyle Holdings I L.P. C/O THE CARLYLE GROUP, 1001 PENNSYLVANIA AVE., N.W. SUITE 220 S WASHINGTON, DC20004-2505 X TC Group, LLC C/O THE CARLYLE GROUP 1001 PENNSYLVANIA AVE., N.W. SUITE 220 S WASHINGTON, DC20004-2505 X TC Group Sub L.P. C/O THE CARLYLE GROUP, 1001 PENNSYLVANIA AVE., N.W. SUITE 220 S WASHINGTON, DC20004-2505 X Signatures Carlyle Group Management L.L.C., By: /s/ Curtis L. Buser, Chief Financial Officer 08/09/2019 Signature of Reporting Person Date The Carlyle Group L.P., By: /s/ Curtis L. Buser, Chief Financial Officer 08/09/2019 Signature of Reporting Person Date Carlyle Holdings I GP Inc., By: /s/ Curtis L. Buser, Chief Financial Officer 08/09/2019 Signature of Reporting Person Date Carlyle Holdings I GP Sub L.L.C., By: Carlyle Holdings I GP Inc., its managing member, By: /s/ Curtis L. Buser, Chief Financial Officer 08/09/2019 Signature of Reporting Person Date Carlyle Holdings I L.P., By: /s/ Curtis L. Buser, Chief Financial Officer 08/09/2019 Signature of Reporting Person Date TC Group, L.L.C., By: Carlyle Holdings I L.P., its managing member, By: /s/ Curtis L. Buser, Chief Financial Officer 08/09/2019 Signature of Reporting Person Date TC Group Sub L.P, By: TC Group, L.L.C., its general partner, By: Carlyle Holdings I L.P., its managing member, By: /s/ Curtis L. Buser, Chief Financial Officer 08/09/2019 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The operating partnership units are redeemable at any time for cash or, at the election of the Issuer, exchangeable for shares of common stock on a one-for-one basis, and have no expiration date. ( 2 )Following the transactions reported herein, consists of (i) 2,082,097 common units held by CoreSite CRP III Holdings, LLC; (ii) 421,780 common units held by CoreSite CRP III Holdings (VCOC), LLC; (iii) 1,459,136 common units held by CoreSite CRP IV Holdings, LLC; (iv) 248,488 common units held by CoreSite CRP IV Holdings (VCOC I), LLC; (v) 638,671 common units held by CoreSite CRP IV Holdings (VCOC II), LLC; and (vi) 5,875,218 common units held by CoreSite CRP V Holdings, LLC. ( 3 )Carlyle Group Management L.L.C. is the general partner of The Carlyle Group L.P., which is a publicly traded entity listed on NASDAQ. The Carlyle Group L.P. is the sole shareholder of Carlyle Holdings I GP Inc., which is the managing member of Carlyle Holdings I GP Sub L.L.C., which is the general partner of Carlyle Holdings I L.P., which is the managing member of TC Group, L.L.C., which is the general partner of TC Group Sub L.P., which is the managing member of each of Carlyle Realty III GP, L.L.C., CRP III AIV GP, L.L.C., Carlyle Realty IV GP, L.L.C., CRP IV AIV GP, L.L.C. and Carlyle Realty V GP, L.L.C. ( 4 )Carlyle Realty III GP, L.L.C. is the general partner of Carlyle Realty III, L.P. which is the manager of CoreSite CRP III Holdings, LLC. CRP III AIV GP, L.L.C. is the general partner of CRP III AIV GP, L.P., which is the general partner of CRQP III AIV, L.P., which is the managing member of CoreSite CRP III Holdings (VCOC), LLC. Carlyle Realty IV GP, L.L.C. is the general partner of Carlyle Realty IV, L.P., which is the manager of CoreSite CRP IV Holdings, LLC. CRP IV AIV GP, L.L.C. is the general partner of CRP IV AIV GP, L.P., which is the general partner of each of CRP IV-A AIV, L.P. and CRQP IV AIV, L.P., which are the managing members of CoreSite CRP IV Holdings (VCOC I), LLC and CoreSite CRP IV Holdings (VCOC II), LLC, respectively. Carlyle Realty V GP, L.L.C. is the general partner of Carlyle Realty V, L.P., which is the manager of CoreSite CRP V Holdings, LLC.

Remarks: Due to the limitations of the electronic filing system Carlyle Realty III GP, L.L.C., Carlyle Realty III, L.P., CoreSite CRP III Holdings, LLC, CRP III AIV GP, L.L.C., CRP III AIV GP, L.P., CRQP III AIV, L.P., CoreSite CRP III Holdings (VCOC), LLC, Carlyle Realty IV GP, L.L.C., Carlyle Realty IV, L.P., CoreSite CRP IV Holdings, LLC, CRP IV AIV GP, L.L.C., CRP IV AIV GP, L.P., CRP IV-A AIV, L.P., CRQP IV AIV, L.P., CoreSite CRP IV Holdings (VCOC I), LLC, CoreSite CRP IV Holdings (VCOC II), LLC, Carlyle Realty V GP, L.L.C., Carlyle Realty V, L.P. and CoreSite CRP V Holdings, LLC are filing a separate Form 4.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.