Remove external links, per ethereum#3358

EIPS/eip-2228.md

@@ -23,7 +23,7 @@ This standard specifies the name for this network and provides reference example
 The Ethereum network with chainid 1 is referenced using several conflicting names across EIPs (as published at the time EIP 2228 was written), client implementations, and information published on the internet at large:
 
 * "main net" at [EIP-155](./eip-155.md), [EIP-170](./eip-170.md)
-* "mainnet" at [EIP-86 [DRAFT]](./eip-86.md), [client documentation](https://geth.ethereum.org/support/FAQ)
+* "mainnet" at [EIP-86 [DRAFT]](./eip-86.md), the Go Ethereum documentation FAQ page
 * "Main net" at [EIP-2](./eip-2.md), [EIP-150](./eip-150.md)
    * \* In EIP-2, it is unclear if the first letter is capital because it is a proper noun or if it is the the first word in a text column presented in sentence case
 * "Mainnet" at [EIP-7](./eip-7.md), [EIP-779](./eip-779.md)
@@ -38,7 +38,7 @@ Any name or word styling (i.e. capitalization of the letters) of the network whi
 
 ### Trademark note
 
-Note: Ethereum [is a registered trademark](https://tsdr.uspto.gov/#caseNumber=86634529&caseType=SERIAL_NO&searchType=statusSearch) of Ethereum Foundation and [the Foundation asserts](https://ethereum.org/en/terms-of-use/) "you must not use [this mark] without the prior written permission of the Foundation".
+Note: Ethereum is a registered trademark (USPTO serial number 86634529, US registration number 5110579) of Ethereum Foundation and "you must not use [this mark] without the prior written permission of the Foundation" (per the Ethereum Foundation website, Terms of Use page).
 
 Your application MAY reference "Ethereum® Mainnet" and include a note "Ethereum is a registered trademark of Ethereum Foundation" elsewhere.