It is used for observations for observations for which there are no special sensitivity considerations and which can be freely shared. Please note:
In some institutional environments the term "unclassified" is used in a sense that still denotes implied restrictions in the circulation of information. If this is the case, this organisation may probably consider that "free" (value F) is not the appropriate corresponding tag for this kind of "unclassified" category and it may be that "non-publishable / restricted" (value N) may be more appropriate.
The focus of this code is not to describe and anticipate all potential permissible uses (e.g. permission to re-disseminate). Thus, the use of "F" does not allow safe assumptions with respect to the permission to "re-disseminate" (freely or at a price) the received or accessed information (e.g. on web or paper), especially on a massive and regular basis (legal and copyright constraints may apply). Usually, source organisations provide information and guidance on re-dissemination issues, either on their websites or on their paper publications. (en)