Churchill always used a red ink pen, so when he was PM during WW2 no one writing anything which he might see was allowed to use one. He tended not to write much other than terse comments on the typed Memoranda of others, signed WSC with a day in Arabic and a month in Roman numerals. For historical researchers it can be an extra, but interesting, step to find out what was happening on the day on which he signed off each.
Traditionally, 'C', Director General of SIS, uses a green fountain pen, and no one else there is allowed to use green ink
I'm sure neither WSC nor any C would abuse an apostrophe
(mere guide at) Jet Age Museum, Gloucestershire Airport
http://www.jetagemuseum.org/TripAdvisor Excellence Award 2015
http://www.tripadvisor.co.uk/Attraction ... gland.html