Ok, if I understand everything; I am able to make an SBR in Washington effective June, 9th, 2016 I plan on making an SBR after I receive my tax stamp. I was reviewing form 1, my question is as follows: What identifying marks do I need to get engraved on the rifle, if any. I have been told multiple things from different sources. I need to engrave a (second) serial number on the lower. I need to engrave a (second) serial number, with caliber information on the lower. I need to engrave a (second) serial number, with state and county engraved on the lower. I dont need to engrave anything and it can be left as is. Or am I totally wrong and we still cant build SBRs in Washington?