diff --git a/namco/boards.md b/namco/boards.md
index 8c5dbec..2542e75 100644
--- a/namco/boards.md
+++ b/namco/boards.md
@@ -189,6 +189,7 @@ ES3(X):
 **RAM:** ??? (8GB) / ??? (16GB)  
 **GPU:** Nvidia GeForce GTX680 / Nvidia GeForce GTX760  
 **HDD:** HGST HTS545025A7E680 (SATA, 250GB, 5400RPM)  
+**IO:** [Namco ESIF2 PCB](io.md#esif2) (above motherboard shield)  
 
 ```
      A - Pokken Tournament
diff --git a/namco/identifiers.md b/namco/identifiers.md
new file mode 100644
index 0000000..85b3b80
--- /dev/null
+++ b/namco/identifiers.md
@@ -0,0 +1,93 @@
+# NAMCO identifiers.
+
+This file describes the various identifiers and their formats that are used in products by NAMCO.
+
+## Generic fields
+
+### Region code
+
+* `1`: JPN
+* `2`: USA?
+* `3`: EXP/ASIA?
+* `5`: CHN
+* `6`: 
+
+### Cabinet role
+
+* `LM`: live monitor?
+* `NA`: normal?
+* `TM`: terminal?
+* `TW`: medal/card game?
+
+## Part number
+
+## Product code
+
+Components:
+- `$g`: game code, `[A-Z0-9]{3}`
+- `$v`: version, `[0-9]`
+- `$r`: revision, `[A-B]`
+- `$l`: [region code (locale)](#region-code), `[0-9]`
+- `$a`: unknown, `[0-9]`
+- `$b`: unknown, `[0-9]`
+- `$c`: [cabinet role](#cabinet-role), `[A-Z]{2}`
+- `$t`: type, `[A-Z]{4}`
+  * `MPRO`: M production? (on ES2 HDD, ES4 HDD)
+  * `HDD0`: HDD (on N2 case)
+  * `DAT0`: data (on ES1 HDD)
+- `$u`: unknown, `[A-Z]{2}`
+
+Formats:
+- `$g$v-$u`
+  * Used in System 256 case, HDD
+  * Examples:
+    - `TSF1-HA`: game code TSF, version 1, $u HA
+- `$g$v$a$b$l-$c-$r`
+  * Used in System 256 dongle
+  * Examples:
+    - `TSF1002-NA-A`: game code TSF, version 1, $a 0, $b 0, locale 2?, cabinet role normal, revision A
+- `$g$v$a$b$l-$c-$t-$r`
+  * Used in System N2
+  * Examples:
+    - `WM31003-NA-HDD0-A`: game code WM3, version 1, $a 0, $b 0, locale Export, cabinet role normal, type HDD, revision A
+- `$g$v$a$b-$l-$c-$t-$r`
+  * Used in System 369, ES1, ES2, ES2+, ES3, ES4
+  * Examples:
+    - `TG2100-2-LM-HDD0-A`: game code TG2, version 1, $a 0, $b 0, locale US, cabinet role live monitor, type hard drive, revision A
+    - `PBN100-1-NA-MPRO-A`: game code PBN, version 1, $a 0, $b 0, locale Japan, cabinet role normal, type M production, revision A
+    - `GCB100-1-TW-MPRO-B`: game code GCB, version 1, $a 0, $b 0, locale Japan, cabinet role TW, type M production, revision B
+
+## Dongle serial
+
+Components:
+- `$d`: drawing code, `[0-9]{4}`
+- `$r`: [region code](#region-code), `[0-9]`
+- `$a`: account code, `[0-9]`
+- `$t`: title code, `[0-9]{2}`
+- `$n`: serial number, `[0-9]{4}`
+
+Formats:
+- `a$d$r$a $t$na`
+  * Examples:
+    - `a274811 260532a`: drawing code 2748, region Japan, account 1, title 26, serial number 0532
+    - `a2793 13393143a`: drawing code 2793, region Japan, account 3, title 39, serial number 3143
+
+Unknowns:
+- System 256 dongle (memory card): `a 026161 351019 a`
+
+## Net ID
+
+Components:
+- `$x`: unknown, `[A-Z]`
+  * `D`:
+  * `E`:
+  * `G`:
+- `$a`: account code, `[0-9]`
+- `$t`: title code, `[0-9]{2}`
+- `$n`: serial number, `[0-9]{4}`
+
+Formats:
+- `AB$xN-$a$t$n`
+  * Examples:
+    - `ABGN-1260532`: unknown G, account 1, title 26, serial number 0532
+    - `ABEN-3393143`: unknown E, account 3, title 39, serial number 3143
diff --git a/namco/io.md b/namco/io.md
index 6cc9602..aed348e 100644
--- a/namco/io.md
+++ b/namco/io.md
@@ -33,11 +33,11 @@ External serial interface. Connects to motherboard serial, and exposes JVS and s
   - Hitachi HD64F3672 (QFP48, H8 MCU)
   - "E 14.7456C" "2PH K487H" (14.7456 MHz crystal)
   - Sipex SP485EC (SOIC8, RS-485 transceiver)
-  - Maxlinear SP3222EUCY (SSOP16, RS-232 transceiver)
+  - Sipex SP3222EUCY (SSOP16, RS-232 transceiver)
 * Connectors:
   - (external) 1x 4pin
   - (internal) 1x 12pin (to motherboard front panel and motherboard serial header, pinout up-down: JF1-RST-L JF1-RST-R JF1-PWRON-L JF1-PWRON-R JF1-HDDLED-L JF1-HDDLED-R JF1-PWRLED-L JF1-PWRLED-R COM-RTS COM-CTS COM-RXD COM-TXD
-  - (internal) 1x 4pin (to power supply 12V and 5V, pinout left-right: GND GND NC GND 12V 5V)
+  - (internal) 1x 7pin (to power supply 12V and 5V, pinout left-right: GND GND NC GND 12V 5V)
   - (internal) 1x 4pin (to JVS expansion card, pinout left-right: V+ D+ D- V-)
 
 ## H058 TSIF
@@ -48,7 +48,7 @@ External interface. Connects to motherboard and exposes a bunch of custom connec
 * Label: H058 TSIF PCB
 * Chips:
   - FTDI FT232RL (SSOP28, RS-232 to USB transceiver)
-  - Maxlinear SP3222EUCY (SSOP16, RS-232 transceiver)
+  - Sipex SP3222EUCY (SSOP16, RS-232 transceiver)
 * Connectors:
   - (external) 1x 3pin  (CN3, SERIAL1, to SP3222EUCY, pinout left-right: GND T1OUT R1IN)
   - (external) 1x 8pin  (CN6, SERIAL2, to CN4, pinout left-right: 12V GND RXD1 TXD1 RTS1 CTS1 GND1)
@@ -69,9 +69,26 @@ External interface. Connects to motherboard and exposes a custom connector, JVS
   - Hitachi HD64F3672 (QFP48, H8 MCU)
   - "14745 KSS 3LF" (14.745 MHz crystal)
   - Sipex SP485EC (SOIC8, RS-485 transceiver)
-  - Maxlinear SP3222EUCY (SSOP16, RS-232 transceiver)
+  - Sipex SP3222EUCY (SSOP16, RS-232 transceiver)
 * Connectors:
   - (external) 1x 7pin  (CN3, SERIAL 3 (CARD IF), pinout left-right: 12V GND RXD1 TXD1 RTS1 CTS1 GND1)
   - (external) 1x USB   (CN4, JV IO (JAMMA))
   - (internal) 1x 20pin (CN2, serial & front panel, pinout up-down left-right: RXD1 TXD1 RTS1 CTS1 GND1 TXD2 RXD2 RTS2 CTS2 NC HDDLED+ HDDLED- PWRLED+ PWRLED- JP2+ JP2- SW2+ SW2- NC NC)
   - (internal) 1x 4pin  (CN1, power, pinout left-right: 5V GND 12V GND)
+
+## ESIF2
+
+External serial interface, revision 2. Looks identical to the [H039 ESIF](#h039-esif). Connects to motherboard serial, and exposes JVS and serial. Likely turns on/resets the motherboard too.
+
+* Product: 8921960100 / (8921970100)
+* Label: ESIF2 PCB
+* Chips:
+  - Hitachi HD64F3672 (QFP48, H8 MCU)
+  - "E 14.7456C" "2PK D494I" (14.7456 MHz crystal)
+  - Sipex SP485EC (SOIC8, RS-485 transceiver)
+  - Sipex SP3222EUCY (SSOP16, RS-232 transceiver)
+* Connectors:
+  - (external) 1x 4pin
+  - (internal) 1x 12pin (to motherboard front panel and motherboard serial header)
+  - (internal) 1x 7pin (to power supply 12V and 5V, pinout left-right: GND GND NC GND 12V 5V)
+  - (internal) 1x 4pin (to JVS expansion card, pinout left-right: V+ D+ D- V-)