TARDIS Information system
The TARDIS Index File' was a searchable database discovered by the Doctor's companions Nyssa and Tegan from a readout on the TARDIS console.
Articles within the database could be accessed by typing in a two letter acronym for the subject. Entering "IF," for example, would bring up the database's Index File. Nyssa noted that using the Index File to search for the Index File was an example of recursion.
It was later revealed that the Master had modified the Doctor's TARDIS via block transfer computation as part of his plan to ensnare the Doctor in Castrovalva. At least some of the TARDIS Index File, such as the entry on Castrovalva, would not nromally exist there. (DW: Castrovalva).
Turlough later read a historical account of Earth's colission with its sun in order to purposefully distress Tegan. (DW: Frontios).
Notes
- The TARDIS Index File website, a collaborative project to create the most definitive, accurate, and accessible encyclopedia and reference database for everything related to Doctor Who uses a database formatted in a WikiWiki structure which visitors can edit, takes its name from this feature of the Doctor's TARDIS.
- The presence of an entry for the TARDIS Index File in the TARDIS Index File Wiki also represents a form of recursion.
