On August 25, 2022, WIPO released an updated version of its helpful "Introduction to the International Phase" and "Introduction to the National Phase" documents, which are available at:
Introduction to the International Phase: https://www.wipo.int/export/sites/www/pct/guide/en/gdvol1/pdf/gdvol1.pdf
Introduction to the National Phase: https://www.wipo.int/export/sites/www/pct/guide/en/gdvol2/pdf/gdvol2.pdf
Of course, country-specific annexes to the International Phase and National Phase guides can also be obtained from WIPO here: https://www.wipo.int/pct/en/guide.
As an aid to users, WIPO provides the most recently updated date at the bottom right corner of each page of a given guide.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.