All references are based on the 2017 edition of the NEC.
I spotted this arrangement on the backside of a scoreboard at a local little league baseball field. The installers apparently forgot about some of the support requirements for wiring methods and boxes. The liquidtight flexible metal conduit (LFMC) installed between the two boxes is completely unsupported, except for the connectors. Section 350.30(A) requires LFMC to be secured within 12