- From: Tobie Langel <tobie@fb.com>
- Date: Wed, 18 Apr 2012 12:47:43 +0000
- To: Cuihtlauac ALVARADO <cuihtlauac.alvarado@orange.com>, "public-coremob@w3.org" <public-coremob@w3.org>, James Graham <jgraham@opera.com>
On 4/17/12 3:51 PM, "Cuihtlauac ALVARADO" <cuihtlauac.alvarado@orange.com> wrote: >Hi Tobie, > >Allow me to express my disagreement with respect to that change, and >such kind of change in general. > >I share your interpretation of RFC 2119. "MUST" is an unconditionally >requirement while "SHOULD" is a conditional requirement (i.e. "there may >exists valid reasons [...] to ignore [...]"). Replacing "MUST if" by >"SHOULD" is formally correct. However, in practice, "MUST if" is far >superior to "SHOULD", the former should be preferred. Let me explain why. > >Basically, the "MUST if" clause comes with text which details the >circumstances under which the requirement does apply, while "SHOULD" >does not. In our case, we absolutely do not want a device which has a >SMS app and the agent is *not* capable to trigger that SMS app using the >sms: scheme. That must be avoided. We really want the URI scheme to be >dispatched always, unless sending SMS is not possible. This was captured >by "MUST ... (if available)", it is no longer by "SHOULD". > > From test implementation perspective, the "MUST if" is easily turned >into a real conditional statement, in contrast, it is impossible to >decide, at test execution time, whether failing to comply with a >"SHOULD" is actually valid or not. > >In practice, "SHOULD" and "MAY" are the same. "MAY" is good for options. >When "MUST" has valid exceptions, positive cases should be detailed in >"MUST if" sentences. "SHOULD" MUST be avoided ;-) > >Cheers. > >https://github.com/coremob/level-0/commit/df3f70c21256bac250e3d5c7b14d9811 >968266af I don't have a strong opinion about this. James Graham requested that change so I'll let you too fight over it. :) --tobie
Received on Wednesday, 18 April 2012 12:48:44 UTC