I've been to several predominantly Muslim countries, and 'dressing modestly' seems to be a bit different in each one. In some it doesn't really matter how you dress, because they have large non-Muslim populations that don't follow the Muslim customs. In some it is important to cover your shoulders, upper arms, and knees. Once or twice I have felf more comfortable in long pants or skirts. I'm expecting that the knees, shoulders, and upper arms are all I'd have to worry about there. Is that a good guideline?