Of some data more than one version can exist in the database. This gives the possibility to keep more values for the data items in the database. This is used to store e.g. nodal unknowns at the old time point t, while the new nodal unknowns are being calculated in the current time step. Moreover, it comes handy at mesh refinements, where data for the old coarse mesh and the refined new mesh are avaiable at the same time, etc. Some of the allowed versions are listed below:
| version | purpose |
| VERSION_NORMAL | Normal working version. Keeps unknowns at old time point t. |
| VERSION_NEW | New mesh. Keeps unknowns at time t+dt. |
| VERSION_START | Keeps the mesh at the start of the calculation; for restarts. |
| VERSION_TMP | Temporarily working version (scratch version). |
| VERSION_PRINT | Temporarily version for printing (some plotters require sequential numbering). |
| VERSION_MACRO | Temporarily version for control_macro option. |
| ... | ... |