PSOC has a cleaner reference stack than the workbook-only view suggests: browse page, API guide, API base URL and the 2022 workbook link all matter.
Browse page: https://psa.gov.ph/classification/psoc
API guide: https://psa.gov.ph/classifications-api/access-guide
API base URL: https://classification.psa.gov.ph/psoc
Workbook link: https://psa.gov.ph/sites/default/files/kmcd/files/2022-Updates-to-the-2012-PSOC.xlsx
The workbook URL is the official PSA publication link, but direct retrieval may be protected by Cloudflare in some environments. The site therefore keeps it as a source reference rather than pretending to have mirrored a clean local copy.
The API docs confirm the current public PSOC structure and are the best source for the major, sub-major, minor and unit grouping layers used in official retrieval workflows.
PSA PSOC overview - main browse source and public version reference
PSA Classification API access guide - API documentation and endpoint reference for PSOC
PSOC API base URL - API endpoint reference for authorized PSOC retrieval
2022 Updates to the 2012 PSOC workbook - official workbook link published by PSA; direct retrieval may be protected in some environments
https://psa.gov.ph/sites/default/files/kmcd/files/2022-Updates-to-the-2012-PSOC.xlsx