A best-by date is another term for a best-before date, a date by which it is ideal that a perishable product is used or consumed.
A lot of foods have a best by date. Usually all of the food in cans, bottles, boxes, and bags have a best by date. Food that doesn't have something protecting over it like fruit and vegetables doesn't have a best by date usually.
Expiration date: Do not use/eat on or after that date. Best if used/eaten by date: Better if used/eaten before that date. Almost the same but when something expires you can't use/eat it.If it just passed the best if used/eaten by date it's ok to use/eat but it's better not to.
the use by date is that is advised to be eaten by... this does not mean to say that is has to be eaten if it is fine if it going moldy it is rotten so throw it away :)
cream crackers are called cream cracker because they used to have cream of tartar in then it was taken out of the ingredients but kept the name
well if its on a food product it means that the food will expire by: whatever the date is. so u better eat it b4 then.
sulphur and phosphorous
No
It is used to make a brighter flash.
Although I can't be 100% positive, it looks like that would be a "Best if Used By" date of 08/23/2017 or August 23, 2017.
when they want to catch insects
Not used in speech often, posterior to today's date is any date after the current one.