I have a question about a pattern I bought online.

Don't worry about that. There's a law that children's pajamas have to be made of flame-resistant material in order to be sold in stores. It's strange that they would have that written on a pattern, but I guess that it's just to let you know that it's recommended that you use flame-resistant material. But you're not selling the pajamas, so it doesn't really matter what material you use. It's just a legal thing that they feel they have to put on the package.

Dealing with patterns is rather fun, sometimes like having a root canal without anesthesia! One of the things you need to keep in mind is that the pattern companies will post this warning to protect themselves from potential law suits. Now days people will sue at the drop of a hat. I use the warning "not recommended for small children due to small parts and the potential of choking" on my teddy bears. Also, if it is a multi sized pattern, it could be that people with smaller children may consider making the garment for sleep wear. I have used various patterns to make sleep wear for both myself and my daughter, including slip patterns, jogging suits and more. It depends on our moods at the time and what looked comfortable. The thing was that I didn't use the slip or jogging suit patterns for my daughter until she was well past the toddler age... up until that time I used regular sleep wear patterns. Also, I have found with Simplicity, that they can be kind of vague in the instruction department...so it isn't unusual that they would make the statement on the pattern that it isn't suitable for sleepwear. It's a mental hot foot at best. I am sure if you were to check the other major pattern companies that they would have the same warning on the pattern envelope. Simply because the probability of the general public would be to make pajamas for children and not buy the flame retardant materials. It became a major point many years ago after so many children were burned badly or killed by fabrics that weren't fire safe. I kept wondering where the parents were, and how come the matches etc weren't put out of reach of small children. Hopefully we both have helped your questions. Also what size pattern are you using, and is it for a boy or a girl? I have some sleep wear patterns that need a new home....