There is a feature to store spaces that have been computed over a particular field. This typically saves a lot of time in many of the routines, because the algorithms use precomputations and data from existing spaces over the same field. However, these objects also occupy a lot of memory.
By default, no caching is done; the user must manually set it for each field. It is recommended to always do this when the field is created, and then clear the cache whenever memory usage becomes a concern.
Note: in earlier versions (prior to V2.20) caching was always switched on for Hilbert modular forms.
If v is true, modular forms over the field F that are created afterwards will be cached. If v is false, the existing cache is made empty and caching is switched off.
The cache of modular forms over the field F is made empty. If caching was switched on for F, it remains switched on.