For a coded departure procedure (SID), Fly-At-Altitude or At-Waypoint instruction has priority in case of conflict?
The textual description says clearly:


  RWY track to 4.5 DME FFM/1.5 DME FRD or 800, whichever is later


The equivalent encoding is:


  [A800+] - DF134 (25C)[L] / DF135 (25L)[L]


The meaning of this is climb to an altitude of 800ft or above, then after passing DF134/DF135 turn left. 

From this EUROCONTROL document (Guidance Material for the Design of Terminal Procedures for DME/DME and GNSS Area Navigation(PDF)):


  [Speed, track and altitude constraints are contained within square brackets.]
  
  If [A Set of Constraints] is not preceded by a waypoint name, the last calculated track must be flown until the constraint is reached


The turn will thus not be initiated before both the 800 ft altitude and the waypoint are reached.