- * \return If \p a is NULL, return a pointer to a copy of \p b, i.e.
- * para_strcat(NULL, b) is equivalent to para_strdup(b). If \p b is NULL,
- * return \p a without making a copy of \p a. Otherwise, construct the
- * concatenation \p c, free \p a (but not \p b) and return \p c.
+ * \return If \a a is \p NULL, return a pointer to a copy of \a b, i.e.
+ * para_strcat(NULL, b) is equivalent to para_strdup(b). If \a b is \p NULL,
+ * return \a a without making a copy of \a a. Otherwise, construct the
+ * concatenation \a c, free \a a (but not \a b) and return \a c.