There are things, methods, ways-of-doing-things - and not only in programming - which are labelled as "proper" and "good". They mostly come from life-long experience and often the reasoning behind them is subtle; the point being to do things in a robust way, somehow taking care of some "common faults" "automagically". Nevertheless, there might be valid (or at least half-reasonable) reasons to shoot one into his foot; as well as there are those out-of-the-standard methods which one has to employ when running against some limitation (it's not really the case of asynchronous transmission).

In this particular case, the mixed method is detrimental if you use the TI flag the other way round, i.e. if you check-and-clear it BEFORE inserting character into SBUF (which is the better way to do things anyway, isn't it). The cautionary note therefore is issued, and if you obey it as you should, you don't run into problems, regardless of what you do with TI.


Sure, for example by TI = 1. ;-)
(OK, if you want something more sophisticated, it can be hidden behind some obscure manipulation with the whole SFR byte).

JW