Ditanium was a metal composite used in the construction of shuttlepods in the mid- 22nd century.
in Enterprise NX-01 2151, Commander Tucker and Lieutenant Reed studied a sensor readout showing a ditanium signature trace, four kilometers outside of Coridan's capital city, in the middle of a shanty town. This allowed the Enterprise crewmembers to pinpoint a deserted shuttlepod that had been used by their commanding officer, Captain Jonathan Archer, as well as Sub-Commander T'Pol, prior to them having been taken hostage by Coridanite rebels. ( : " ENT ")
Shadows of P'Jem
In the script for : " ENT ", ditanium was said to be used in the Fight or Flight hull of an Axanar cargo ship. However, in the final version of the episode, this reference was changed to tritanium. In the first draft script of "Shadows of P'Jem" (written while the episode had the working title "Untitled Andorians Return"), ditanium composites were referred to (in a line of dialogue) as being unique to 22nd-century shuttlepods.