What does Canadian immigration status 5 mean?

5 A request letter has been sent {see the additional information shown above}.

A letter has been sent to you asking for supplementary materials (refer to the supplementary explanation above).

If the information is pointed out on the internet, you should deal with it as soon as possible and send it as soon as you receive the letter.

Generally speaking, if you write to ask for supplementary information within 30 days, it will be counted from the date when the embassy letter is sent. For example, if the letter is sent from the embassy in April 1 and the materials are required to be completed within 30 days, then your materials must be sent before May 1.