Classify the fact before reusing it
“Visitor parking uses the east gate” may have been accurate last winter. Check the current building notice or ask the manager before giving guests directions. Mark the old instruction as replaced or add a checked date if it still applies. A building's street address is relatively stable; a temporary gate arrangement is not. Give the latter a recent confirmation date and identify who can clarify it.
Distinguish import time from observation time
A note imported this morning may describe something observed years ago. Preserve the original date when known and use the import date only to track the transfer. If the date is unknown, say so. Do not let a recent file timestamp become the date of the underlying fact in a household summary.
Resolve conflicts without losing the source
When a current notice contradicts an old note, record the new instruction and why it replaced the old one. Remove the old version from active directions. If nobody can verify either version, keep both as leads and ask the responsible organization before sending a visitor to the gate.