Hello all, The function \scan_align_safe_stop: is deprecated for removal after the end of 2016. In place of this function, programmers should ensure that functions testing for example \mode_if_math:TF are protected Reasoning. \scan_align_safe_stop: was originally introduced in an attempt to allow fully expandable mode tests at the start of alignment cells, etc. However, after reviewing the original code the team realised that this was not a viable approach. The current \scan_align_safe_stop: is therefore simply a protected version of \prg_do_nothing:. However, this adds nothing to making the calling function itself protected. -- Joseph Wright