However some recipes are actually common to more than one book. I was caught out by this last night when making Iron bars.
The first sign I had of something strange was hitting Indurate and getting the message "This recipe does not use Weaponry". I then had a "Major Knot" in my Iron bar
![Smiley: smile](http://zam.zamimg.com/i/smilies/smile.gif)
On investigating I have three recipes for iron bar. One using Weaponry, one using fletching and one using Runecraft. It is fairly important to choose the right recipe or you end up in a pickle and unable to use your durability buffs.