diff --git a/hash/megadriv.xml b/hash/megadriv.xml
index 5e061d9fb61..b90918c14d8 100644
--- a/hash/megadriv.xml
+++ b/hash/megadriv.xml
@@ -27876,6 +27876,10 @@ Official modification of rev. A which changes the spike damage behavior to be li
 		<description>Sonic The Hedgehog 2 (prototype)</description>
 		<year>1992</year>
 		<publisher>Sega</publisher>
+		<notes><![CDATA[
+Presumably built sometime between June and early August of 1992.
+Originally found in a pirate cartridge, an official prototype with this build has been found and proved to match.
+]]></notes>
 		<part name="cart" interface="megadriv_cart">
 			<dataarea name="rom" width="16" endianness="big" size="1048576">
 				<rom name="sonic the hedgehog 2 (prototype).bin" size="1048576" crc="eea21b5c" sha1="2f3228088b000260c2e00961efb0ed76629c84e9"/>
@@ -27884,9 +27888,12 @@ Official modification of rev. A which changes the spike damage behavior to be li
 	</software>
 
 	<software name="sonic2b" cloneof="sonic2">
-		<description>Sonic The Hedgehog 2 (World, rev. 01a)</description>
+		<description>Sonic The Hedgehog 2 (World, rev. A, ripped from Sonic Mega Collection)</description>
 		<year>1992</year>
 		<publisher>Sega</publisher>
+		<notes><![CDATA[
+Official modification of rev. A which fixes the 14 continues cheat sound bug.
+]]></notes>
 		<info name="serial" value="G-4088 (JPN)"/>
 		<info name="release" value="19921121 (JPN)"/>
 		<info name="alt_title" value="ソニック・ザ・ヘッジホッグ2"/>
@@ -27898,7 +27905,7 @@ Official modification of rev. A which changes the spike damage behavior to be li
 	</software>
 
 	<software name="sonic2c" cloneof="sonic2">
-		<description>Sonic The Hedgehog 2 (World, rev. SC02)</description>
+		<description>Sonic The Hedgehog 2 (World, rev. B, ripped from Sonic Compilation)</description>
 		<year>1992</year>
 		<publisher>Sega</publisher>
 		<info name="serial" value="G-4088 (JPN)"/>
@@ -27912,10 +27919,15 @@ Official modification of rev. A which changes the spike damage behavior to be li
 	</software>
 
 	<software name="sonic2p1" cloneof="sonic2">
-		<description>Sonic The Hedgehog 2 (World, prototype)</description>
+		<description>Sonic The Hedgehog 2 (early prototype)</description>
 		<year>1992</year>
 		<publisher>Sega</publisher>
+		<notes><![CDATA[
+Built sometime before June 1992.
+Contained in four EPROMs, labeled: "SONIC 0", "1", "2", "3".
+]]></notes>
 		<part name="cart" interface="megadriv_cart">
+			<feature name="pcb" value="171-5694-01"/>
 			<dataarea name="rom" width="16" endianness="big" size="1048576">
 				<rom name="sonic the hedgehog 2 (world) (beta).bin" size="1048576" crc="39faaa70" sha1="5b51b4d98cb4a7a38157dc4ab9462164dd224bfd"/>
 			</dataarea>
@@ -27923,7 +27935,7 @@ Official modification of rev. A which changes the spike damage behavior to be li
 	</software>
 
 	<software name="sonic2p9" cloneof="sonic2">
-		<description>Sonic The Hedgehog 2 (World, prototype 19920821)</description>
+		<description>Sonic The Hedgehog 2 (Alpha, 19920821)</description>
 		<year>1992</year>
 		<publisher>Sega</publisher>
 		<part name="cart" interface="megadriv_cart">
@@ -27957,7 +27969,7 @@ Original scene release which was altered to include a cracktro and bypass the co
 	</software>
 
 	<software name="sonic2p10" cloneof="sonic2">
-		<description>Sonic The Hedgehog 2 (World, prototype 19920914)</description>
+		<description>Sonic The Hedgehog 2 (Pre Beta, 19920914)</description>
 		<year>1992</year>
 		<publisher>Sega</publisher>
 		<part name="cart" interface="megadriv_cart">
@@ -27971,7 +27983,7 @@ Original scene release which was altered to include a cracktro and bypass the co
 	</software>
 
 	<software name="sonic2p11" cloneof="sonic2">
-		<description>Sonic The Hedgehog 2 (World, final prototype 19921102)</description>
+		<description>Sonic The Hedgehog 2 (final prototype, 19921102)</description>
 		<year>1992</year>
 		<publisher>Sega</publisher>
 		<part name="cart" interface="megadriv_cart">
@@ -28022,7 +28034,7 @@ Original scene release which was altered to include a cracktro and bypass the co
 	</software>
 
 	<software name="sonic3up" cloneof="sonic3">
-		<description>Sonic The Hedgehog 3 (USA, prototype 19931120)</description>
+		<description>Sonic The Hedgehog 3 (prototype 19931120)</description>
 		<year>1994</year>
 		<publisher>Sega</publisher>
 		<sharedfeat name="compatibility" value="NTSC-U"/>
@@ -28037,7 +28049,7 @@ Original scene release which was altered to include a cracktro and bypass the co
 	</software>
 
 	<software name="sonic3p1" cloneof="sonic3">
-		<description>Sonic The Hedgehog 3 (World, prototype 19931103)</description>
+		<description>Sonic The Hedgehog 3 (prototype 19931103)</description>
 		<year>1993</year>
 		<publisher>Sega</publisher>
 		<part name="cart" interface="megadriv_cart">