FLAM supports four compression modes: adc, cx7, cx8, and vr8. In the adc, cx8, and vr8 modes, it creates the FLAMFILE as a binary file. Mode adc is the most efficient one. It compresses the datastream by removing the redundancy of repetitive sequences and can be used universally. The other modes mainly eliminate "vertical redundancy", i.e. their efficiency relies on the recognition of re-occurring column contents in table-structured data.
Compression mode adc can be combined with one of two encryption methods supported by FLAM. The first is AES, that has been declared standard for US government agencies by NIST (National Institute of Standards and Technology), the second - flamenc - is a proprietary algorithms of limes datentechnik gmbh. None of the other compression methods allows encryption.
In all binary modes the compressed information is largely independent of the characteristics of the system on which the compression took place, i.e. the FLAMFILEs must not be modified, for example, if they are transmitted on a line which translates codes automatically.
FLAMFILEs which are compressed in the cx7 mode, on the other hand, are insensitive to code translations, since they represent all control information by means of alphanumeric characters, the codes for which are standardized internationally in the ASCII and EBCDIC systems. Providing the original data is character-coded and suitable for exchange between systems with different character sets, the information content of the FLAMFILE remains fully intact after it has been converted to the character set of the destination system, despite the altered binary contents, thanks to the character-oriented interpretation.
The compression mode is identified automatically when the file is decompressed. The user thus does not need to know the compression mode in order to decompress a file.