Yes.  The text states…

A.R. 5.3. May referees use electronic aids or field-marking sprays? RULING: Yes.

As of the 2012-2013 posting of the rule book, the rules were clarified explicitly approving the use of vanishing referee spray.  See change here under rule 5.3 (posted 4/30/12)…

https://refedge.com/wp-content/uploads/2016/04/2012-and-2013-Soccer-Rules-Changes-Posted-4-30-12.pdf

See the 2014-2015 rules here (rule 5.3)…

https://refedge.com/wp-content/uploads/2016/04/Soccer_14-15_Rule_Book.pdf