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Veda Conventions
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.. note::
    Veda has made a large number of choices that might appear quite arbitrary. Some of them are explained here.

Tags like `~FI_T` and `~FI_Process` do not support the Region dimension in SubRES files
    * The vision behind SubRES files is to describe a sub-part of the overall RES, like hydrogen production for example, purely as a technology repository that can be easily shared across models. One would typically use the `TFM_AVA` tag to control availability of technologies across regions and apply regional multipliers via `TFM_UPD`.

SysSettings is imported at the end of each Sync operation
    * SysSettings is where you declare the default interpolation options.

BY_Trans sees only VT files and SubRES trans files see only their own SubRES
    * This is to respect an obvious requirement: Start from scratch and any partial import of a set of files should produce the same output.

'UC_T' tags are supported only in Scenario files (not in VT, SubRES, or Trade)
    *

`VT files` don't support `TFM tags`
    * `TFM tags` are most useful when they can access a large part of the RES. If they were supported in VT files then they would see only the processes that are defined in the same VT file. They are supported in `BY_Trans` instead, where they can access all VT files.