You are probably safe with the Pan-Turkic Latin alphabet. It seems that
this was adopted followng the First Turkology Congress, held in Baku in
1926, see
http://www.azer.com/aiweb/categories/magazine/81_folder/81_articles/81_turkology_congress.html.
Not safe unless you *know* exactly when a character was invented.
Characters adopted into new standardized new Latin-based alphabets or new standardized Latin-based transcription systems often have a previous history.
Jim Allan
