From Redump Wiki

This page outlines the standard format that Sony uses to serialize all PlayStation and related media. In general, the format is four letters followed by five digits, sometimes displayed with a hyphen or space between.
These serials likely originated from industry standard part numbers (規格品番) which are given to media such as CDs and DVDs in Japan as per the Recording Industry Association of Japan's RIS504 standard

Serial ranges typically start at 1, i.e. 00001-01000. For example, SLPM-67000 belongs to the SLPM-66xxx range.

This page does not include PS3, PS4, or PS5 serials. For a full list of Sony PS1/PS2 serials, see https://sony.redump.info/

Contents 1 Japan/Asia 1.1 Retail Serials (S_P_) 1.1.1 SCPS 1.1.2 SCPM 1.1.3 SCPN 1.1.4 SIPS 1.1.5 SLPS 1.1.6 SLPM 1.1.7 SLPN 1.1.8 SRPM 1.2 Multimedia Game Serials (E_P_) 1.2.1 ESPM 1.3 Not for Sale Serials (P_P_) 1.3.1 PAPX 1.3.2 PBPX 1.3.3 PCPX 1.3.4 PCPD 1.3.5 PDPX 1.3.6 PEPX 1.3.7 PTPX 1.3.8 PUPX 1.4 Other 1.4.1 SCZS 1.4.2 PSXC

Japan/Asia

These serials were allocated by Sony Computer Entertainment Japan (SCEJ) and include Asia-region and Korea-region discs that were published early 2003 and prior. Asia/Korea-region discs later received their own serial prefixes.

Retail Serials (S_P_)

SCPS

First Party game discs:

10xxx - Japan PS1 CD original releases
110xx - Japan PS2 CD original releases
15xxx - Japan PS2 DVD-5 original releases
170xx - Japan PS2 DVD-9 original releases
175xx - Japan PS2 DVD-5 Linux release discs
180xx - Japan PS1 Hardware Bundles (e.g. Controller Bundle)
190xx - Japan PS1 PlayStation Comic series
1910x - Japan PS2 CD "PlayStation the Best" re-releases
1915x - Japan PS2 CD P"layStation the Best" re-releases
192xx - Japan PS2 DVD-5 "PlayStation the Best" re-releases
1925x - Japan PS2 DVD-9 "PlayStation the Best" re-releases
193xx - Japan PS2 DVD-5 "PlayStation the Best" re-releases
40xxx - Japan PS1 EPS Series (Music discs)
45xxx - Asian PS1 CD original releases
460xx - Korea PS1 CD original releases
510xx - Asian PS2 CD original releases
550xx - Asian PS2 DVD-5 original releases
559xx - Asian PS2 DVD-9 original releases
560xx - Korea PS2 DVD-5 original releases
7200x - Japan PS2 DVD-5 "Mega Hits" re-releases
91xxx - Japan PS1 CD "PlayStation the Best" and "PSone Books" re-releases

SCPM

First Party Bundled/Not-for-Sale game discs

8500x - Japan PS1 CD Bundled disc
8510x - Japan PS2 CD Bundled disc
8530x - Japan PS2 DVD-5 Bundled disc

SCPN

First Party network adapter bundled discs

601xx - Japan PS2 CD/DVD-5 (PlayStation BB Navigator discs)

SIPS

International (Non-Japan) developed games published by Sony for the Japan region

600xx Japan PS1 CD

SLPS

Third Party Discs

00xxx - Japan PS1 CD original releases
01xxx - Japan PS1 CD original releases
02xxx - Japan PS1 CD original releases
03xxx - Japan PS1 CD original releases
20xxx - Japan PS2 CD
25xxx - Japan PS2 DVD-5
29xxx - Japan PS2 DVD-9
715xx - Japan PS2 CD "PlayStation the Best" re-releases
725xx - Japan PS2 DVD-5 "PlayStation the Best" re-releases
730xx - Japan PS2 CD "PlayStation the Best" re-releases
731xx - Japan PS2 CD "PlayStation the Best" re-releases
732xx - Japan PS2 DVD-5 "PlayStation the Best" re-releases
734xx - Japan PS2 DVD-5 "PlayStation the Best" re-releases
739xx - Japan PS2 DVD-9 "PlayStation the Best" re-releases
91xxx - Japan PS1 CD re-releases

SLPM

Third Party Discs

55xxx - Japan PS2 DVD-5
60xxx - Japan PS2 CD
61xxx - Japan PS2 DVD-5
62xxx - Japan PS2 CD
63xxx - Japan PS2 CD
645xx - Korea PS2 CD 
65xxx - Japan PS2 DVD-5
66xxx - Japan PS2 DVD-5 (incl. SLPM-67000)
670xx - Japan PS2 DVD-9
675xx - Korea PS2 DVD-5
680xx - Japan PS2 CD
685xx - Japan PS2 DVD-5
6900x - Japan PS2 CD
740xx - Japan PS2 CD
741xx - Japan PS2 CD
742xx - Japan PS2 DVD-5
743xx - Japan PS2 DVD-9
744xx - Japan PS2 DVD-5
749xx - Japan PS2 DVD-9
80xxx - Japan PS1 CD
84xxx - Japan PS1 CD
86xxx - Japan PS1 CD
87xxx - Japan PS1 CD
885xx - Korea PS1 CD
89xxx - Japan PS1 CD (Bookstore/Special)

SLPN

Third Party Network adapter bundled discs

4000x - Japan PS2 CD/DVD-5

SRPM

Unknown meaning

7020x Japan PS2 DVD-5 (Multimedia)

Multimedia Game Serials (E_P_)

ESPM

Unknown meaning of E prefix

700xx Japan PS1 CD Multimedia

Not for Sale Serials (P_P_)

Internal, promo, not-for-sale, general Hibaihin discs

PAPX

900xx - Japan PS1 CD
901xx - Japan PS1 CD
902xx - Japan PS2 CD (90237 is a PC disc)
903xx - Japan PS2 CD
905xx - Japan PS2 DVD-5
965xx - Japan DVD-Video
985xx - Japan DVD-Video
985xx - Japan DVD-Video
9900x - Japan VHS

PBPX

950xx - Japan PS1 CD
952xx - PS2 utility discs (201-251)
955xx - PS2 discs (501-525)
956xx - PS2 bundle (601 only)

PCPX

Japan not-for-sale/promo discs

900xx - Japan VHS tapes
960xx - Japan mixture of PS1 CD, VHS tape, Audio CD, DVD-Video
98xxx - Japan mixture of DVD-Video and PS2 DVD-5

PCPD

Not-for-Sale Mini CD

9950x - Japan PS1 Mini-CD (PlayStation Club)

PDPX

Unknown meaning.

9900x - Japan PS2 CD (only known example is an internal serial of SCZS-94101)
9910x - Japan PS2 CD

PEPX

These service discs are printed and manufactured in Japan but intended for use on PAL-region consoles.

1000x - PS2 CD
9400x - PS1 CD

PTPX

These services discs are only known to be used on Japan-region consoles.

97xxx - Japan PS1 CD

PUPX

These service discs are printed and manufactured in Japan but intended for use on USA-region consoles.

93xxx - Japan PS1 CD and PS2 CD

Other

SCZS

Official Fan Book discs

9410x - Japan PS1 CD

PSXC

PSX Update discs

 0020x - Japan PSX CD