[This was included as a self-decoding answer in the posting of Exercise #13; see exercise.013] Answers to Around the Bend #13: (a) No. (b) No. In other words, a blank line will produce a \par if and only if endline characters are present and have catcode 5. It is interesting to note that two consecutive endline characters are not translated simply to \par, but to \par. (The space will disappear in some circumstances, e.g., after a control word, according to TeX's normal scanning rules.) This is the reason (or at least one reason) that a \par operation must perform an implicit \unskip operation. There was also a recent post to comp.text.tex by Donald Arseneau to point out the problem with someone's delimited-argument macro definition: \def\something#1.\par{} The delimiter string ".\par" did not match the actual text ... some text. because of the space token following the period..