My strict rule : Never write/store documentation that is separate from underlying 0s & 1s. It always goes out of sync.

We are currently in the process of creating a data dictionary for our company.

I put down a rule that we are not ever going to create a SEPARATE WordDoc/Wiki/Evernote/GenZ-tool.

If it is code, document its meaning (english explanation for laymen) in the doc string. If it is data, document its meaning in the column's metadata (all database systems provide a property/comment/description capability at table & column level). If it requires complex diagrams, put these in whatever files (doc/image/pdf/mp3), store it as a blob in a database and create a link it in original code comments/column metadata.

All this data is then constantly pulled into some data-mart on top of which a query-able UI is created.

Every documentation must be literally "Tied" to actual systems making money for the company.

If a new code/data is created or updated, and it's missing documentation, PR is not approved. Once the basic technical setup of tying code/data with comments/metadata is done, enforcing this rule of updating documentation is the job of management/CTO culture.