The certificate of vaccination
A traveller bound for the tropics or the East was asked at a sanitary aerodrome whether he was immune. The International Sanitary Convention for Aerial Navigation, signed at The Hague on 12 April 1933, says what counted: a vaccination against smallpox less than three years and more than twelve days old, against cholera less than six months and more than six days old, proved by a written certificate of a doctor whose signature was officially authenticated, or countersigned by the medical officer of a sanitary aerodrome or by a person authorised to witness a passport application.
No certificate of the period has been found and the convention annexes no model, so the paper Bearer prints is a reconstruction on those articles, and the office says so above it.
Bearer makes an investigator's papers for Call of Cthulhu and any 1920s or 1930s tabletop campaign: the passport a consul would have filled in, with the visas and frontier stamps a campaign leaves in it, and the permits, certificates and tickets of the period, to print or to share.
An example

Open this example in the office
The paper
| Offered | from 21 October 1920 |
| Printed in | English |
| Sheets | 1 |
| How it is known | a reconstruction: no document of the period has been found |
A reconstruction
This paper is a reconstruction. No certificate of vaccination of the period has been found, and no convention annexes a model: the International Sanitary Convention for Aerial Navigation of 1933 says what the certificate had to prove and how the doctor's signature was made good (arts. 32 and 35: smallpox within less than three years and more than twelve days, cholera within less than six months and more than six days). The words and the layout are ours.
The same paper elsewhere
Still to be confirmed
- the whole paper: its words and layout. What would settle it: a certificate of vaccination of 1920 to 1939.
- before the convention of 1933 the paper still names the authentication, without the article. What would settle it: a certificate of the twenties.
Sources
- League of Nations, Treaty Series, vol. CLXI, No. 3706, International Sanitary Convention for Aerial Navigation, signed at The Hague, April 12th, 1933, art. 32 (proof of vaccination against cholera within less than six months and more than six days: a written certificate signed by a doctor, his signature officially authenticated, failing which countersigned by the medical officer of a sanitary aerodrome or by a person authorised to witness an application for a passport); art. 35 (smallpox: vaccinated within less than three years and more than twelve days, proved by a doctor's certificate authenticated in the same manner) (read directly)
Open the passport office · MGS Toolbox