The CFI is attributed to a financial instrument at the time when the financial instrument is issued and when it is allocated an International Securities Identification Number (ISIN) by the respective national numbering agency (NNA).
[1] Each of the six letters of the CFI represents a specific characteristic of the financial instrument (e.g. ESVUFB is used to describe a typical registered share).
The CFI code is meant to provide the most comprehensive information possible, while at the same time maintaining the code manageability, provides a standard for identification of type of instrument and their main high level characteristics, determined by the intrinsic characteristics of the financial instrument, which would be independent of the individual names or conventions of a given country or financial institution.
This principle avoids confusion arising from different linguistic usage as well as redundancy, while allowing an objective comparison of the instruments across markets.
[1] CFI codes also aim to simplify electronic communication between participants, improve understanding of the characteristics of financial instruments for the investors, and allow securities grouping in a consistent manner for reporting and categorization purposes.