On 12/02/2010, at 5:56 AM, Joseph Wright wrote: > On 11/02/2010 18:26, Philipp Stephani wrote: >> >> I wonder what the guarantees about the scratch variables like \l_tmpa_tl are. The documentation just states that "they are not used by conditionals or predicate functions." Does this mean that any other kernel macro might modify them? > > A quick search shows they are used in the tl module. I'd stick to defining "private" scratch variables. Should we change this? I.e., use \l_kernel_tmpa_tl or \l_reserveda_tl instead for us and let package writers use \l_tmpa_tl ? -- Will