Sentinel is a web directory organised on a simple principle: every listing must be on the record. That means a live, resolving domain, a submitted entry, and a category placement that reflects what the operator actually does. The directory carries 832 filings spread across 22 subject desks. The desks range from specialist operations — the eight-entry Records & Documents desk and the five-listing Property Beat — to high-volume bureaus such as the 189-entry General Dispatch and the 117-filing Gaming Bureau. Sentinel covers the web as it is, not as any editorial line might prefer it. Operators, agencies, and site owners submit listings through the Add a Site form. Submissions are checked for a live domain before an entry is placed in the relevant desk. Sentinel does not assess financial standing, regulatory compliance, or service quality — those are matters between operators and the readers who contact them. Sentinel is free to list in. There are no placement fees, no premium tiers, and no paid positioning within category desks. Every verified listing sits in the same file alongside every other entry under its subject heading. The directory is maintained on an ongoing basis. Readers who identify a listing that no longer resolves, or who wish to report a submission error, are invited to use the contact channels on the Add a Site page.