This post has been amended 7/30/11
Thanks for your many comments in response to part one. I was unable to respond more promptly due to a spotty internet connection over the past two days.
Kate mentions in comments (and this post was accordingly amended) that she thinks the confusion arises at L’s company based on the description and instruction of an “inset cap sleeve” found in Metric Pattern Cutting, page 108/109 of the 1997 edition (see image below). She also mentions that Shoben’s book shows much the same and Donna mentions that Armstrong does as much. Counterpoint and contradiction arises with Nowak’s mention that Aldrich’s children’s wear book (pg. 109, 3rd edition) illustrates a cap sleeve to be like the fitted short sleeve. Kate further suggests that a straight hemmed cap sleeve seems to be more typical in the UK, perhaps because Aldrich and Shoben are used almost exclusively there. So it would seem the definition of a cap sleeve could largely be regional.
I had been instructed that a cap sleeve looked more like what Aldrich describes as a “fitted short sleeve” (#7) on page 49 (Anir’s link, do check it out). Coincidentally, I discover I don’t have this book. Imagine! I’d confused this title with others I have of hers so I will amend the oversight promptly. I see there’s a new edition too. [Anir: any email I send you bounces.] Again, Nowaks points us to Aldrich’s children’s wear book (pg. 109, 3rd edition) that illustrates a cap sleeve to be like the fitted short sleeve. The only difference being that the cap itself seems a bit flattened. So, we have plenty of confusion and contradiction to go around. Maybe Winifred is as uncertain as we are?
Judging from comments, the educators and old school practitioners (including me) in our midst seem to think the short fitted sleeve is a cap sleeve so maybe the difference is also generational?
Our friends in the UK posit the cap sleeve has a straight hem, possibly owing to the influence of Aldrich and Shoben with the contradiction that Aldrich’s children’s book shows a curved hem on a cap sleeve.
Other people in a position to know (designers and adept enthusiasts) seem to have mixed response with a slant among designers toward the short fitted sleeve being a cap sleeve.
I don’t know the answer. What is certain is that an ambiguity exists where I didn’t realize there was one. That is very good to know. Meaning, one must rely on an illustration which is best anyway.
To L, your answer is this: Regardless of what you call it, if your team wants the look of the “short fitted sleeve”, the hem must be curved. Cutting it that way would probably eliminate the winging of the sides of the sleeve.