Interesting…Thor's Hammer is included.
There are 50 symbols currently allowed on the gravestones of US military personnel. The Wiccan pentacle was only approved in 2007 after a fight that invoked President George W Bush's views on the faith, though other symbols, such as Thor's Hammer, have been added with less of a fight. Most recently a Sandhill Crane was approved for the first same-sex spouse member buried in a military cemetery. Military gravestones are very light on symbolism, however, compared to older religious gravestones or, say, the Victorians.
https://www.metafilter.com/129820/Grave-symbols-of-many-faiths