“Short snorters” (at least the wartime versions) were money carried by soldiers who then had friends and fellow soldiers sign them as souvenirs of their tour of duty. If you ran into someone after signing a note for them and they no longer had it, they owed you a drink (a “short snort”). A few examples are shown here, but for a real dive into the topic, you should visit shortsnorters.org.
A few samples-