Check the PDF properties. Create date should be within the last 3 years for most active DEPs. If not, flag it to document control.
If you are a Shell employee or a long-term contractor with a Shell-issued login, the primary source is the intranet. Shell Dep Standards Download
Most large engineering firms (e.g., Worley, Technip Energies, KBR, Fluor) have licenses to use Shell DEPs on specific projects. Check the PDF properties
Because these documents are confidential, they are strictly distributed through controlled channels. 1. Official Access via Shell DEPs Online Shell Dep Standards Download