## Changes Introduced in V4.3

The following describes the most significant changes which occurred in the AST library between versions V4.2 and V4.3:

1. The astGetFitsS function now strips trailing white space from the returned string, if the original string contains 8 or fewer characters

2. The SpecFrameSpecFrame class has a new attribute called SourceSysSourceSys that specified whether the SourceVelSourceVel attribute (which specifies the rest frame of the source) should be accessed as an apparent radial velocity or a redshift. Note, any existing software that assumes that SourceVel always represents a velocity in km/s should be changed to allow for the possibility of SourceVel representing a redshift value.