TAGGED STAMPS

Tagging the stamps with phosphorescent coating allows them to be easily seen under shortwave (200-300 nm (nanometers)) ultraviolet (UV) light.
When tagging is exposed to strong shortwave UV light, tagged stamps glow a bright color that ranges from yellow-green to bluish green.

Untagged stamp
Tagged Stamp - Overall Tagging
Tagged Stamp - Block (partial) Tagging (untagged margins)