Each errors should be reported according to a standard.
An error should start with: "ERROR", followed by the name of the error, a minus symbol "-", and finally its details. For example, if the test file 'file1.xyz' is missing 'origin' and 'date' from its header, and 'file2.xyz' is missing 'flight id', the program output will be:

ERROR: INCOMPLETE_HEADER - file1.xyz=[date,origin] file2.xyz=[flight id]

Important: In case of multiple files and multiple parameters, the output is organized alphabetically.

Error	Description	Error Name	Error Detail(s)	Example
Invalid option	Unrecognized option given to the program	INVALID_OPTION	the requested option	ERROR: Invalid Option -o x (or --ouput x) is not recognized
Missing command line parameters	Required parameter(s) given options are missing	INVALID_OPTION	the requested parameter	ERROR: Invalid Option -o x (or --ouput x) is missing a parameter
Not implemented	An option is not (yet) implemented	INVALID_OPTION	the requested option	ERROR: Invalid Option -o x (or --ouput x) has not been implemented yet
Invalid Metadata	The requested metadata is invalid	INVALID_OPTION	the requested metadata	ERROR: Invalid Option -m (or --output xxxx) is not a valid metadata
Missing file	A file given as an input is not found	MISSING_FILE	the file name(s)	ERROR: MISSING_FILE - file1 file2 file3
Encoding problem	The content of a file has encoding problems (ascii, utf-8, etc)	ENCODING	the file name(s)	ERROR: ENCODING - file1 file2 file3
Corrupted file	The file cannot be open because of incorrect binary data	CORRUPTED	the file name(s)	ERROR: CORRUPTED - file1 file2 file3
Missing header	The header section is not in the file	MISSING_HEADER	The file name(s)	ERROR: MISSING_HEADER - file1 file2
Incomplete header	The header is missing some information	INCOMPLETE_HEADER	file_name=[info1, info2...]	ERROR: INCOMPLETE_HEADER - file1=[origin,flight id] file2=[date]
Missing columns	Some required columns are not in the file	MISSING_COLUMN	file_name=[col1,col2]	ERROR: MISSING_COLUMN - file1=[timestamp] file2=[longitude,latitude]
Missing column names	The log file does not contain the column names	MISSING_COLNAMES	the file name(s)	ERROR: MISSING_COLNAMES - file1 file2 file3
Incorrect timestamp ordering	The log file is not presenting data lines in a timely ordered way	ORDERING	The file name(s)	ERROR: ORDERING - file1 file2 file3