A unity check of 999.00 is given to indicate that (a part of) the unity check has not been executed. The value of 999 can be seen in the steel checks, composite checks, timber checks and aluminium checks.
Below you can find an example of this behaviour:
the combined bending and axial compression check is not executed if the critical Euler load Ncr is lower than the design compression force NEd:
For the concrete checks a value of 3.00 indicates that a unity check results in an error. In that case the description of the error gives additional information.