\label{Spreadsheet_Import_Values}
The spreadsheet determines which data it imports from the metadata of
the resource. Additional imported values can be used in formulas
through the same \&EXT (external) function that is also available in
assessments. For example, \&EXT("system.time") imports the system
time. (Note that in this particular example, the explicit time
dependence is not recognized by the caching mechanism (see also
\ref{Spreadsheet_Completely_Recalc}). 