There is no doubt that Sekanjabin is a rather popular drink in the SCA, this popularity probably started with Cariadoc's Miscellany with the recipes given for a modern version of the drink and a simple version from the Andalusian Cookbook.
In both the traditional and modern context, a Sekanjabin drink is a sweet and sour syrup based beverage... as it was in the medieval context. Like then, as it is now, it is also considered to be medicinal as well as refreshing as we all know it to be! Now, just because it is medicinal does not necessarily mean the inclusion of herbs and other medicinal ingredients as the vinegar itself was, and still is, purported to have such properties.
Today we can find all sorts of traditional recipes for sekanjabin that go beyond sugar/honey and vinegar which can include various ingredients from mint, cucumber, cinnamon, lemon balm, ginger, lemon, lime, cucumber and various flower waters. Over all, it should keep the Sweet-Sour taste and be made with a sugar/honey and vinegar combination.
What does tend to be cause for confusion is the name used in conjunction with many other sugar-syrup based drinks, usually these could be better classified as Sherbets (among other names, and not to be confused with the frozen dessert) while Sekanjabin could be said to be a sweet and sour Sherbet.
Going back to the Andalusian Cookbook we can find about 30 different drink/syrup recipes (and more can be found through other sources), many of which are sweet, some with spicy overtones and many being quite tasty! Some I have tried was the ones for Apples, Carrots, Tamarind, Lemon, Lavender, Pomegranates, Sekanjabin, Basil, Violets, Mint, Mastic, Julep and Citron Leaves and was not disappointed, however only one of these could be said to be Sekanjabin even though Tamarind and Lemon do possess a sour flavour.