The following abbreviations are used in this manuscript:
Am-GaN	ammonothermal gallium nitride
DB	dislocation bundle
DSE	defect selective etching
FWHM map	full-width at half-maximum map
GaN	gallium nitride
GND	geometrically necessary dislocation
HCD	honeycomb defect
HVPE-GaN	hydride vapor-phase epitaxy gallium nitride
INT map	integrated intensity map
L-XRT	Lang technique X-ray topography
PPOS map	peak position angle map
RCI	synchrotron monochromatic rocking curve imaging
SWB-XRT	synchrotron white-beam X-ray topography
TD	threading dislocation
TED	threading edge dislocation
TMD	threading mixed dislocation
TSD	threading screw dislocation
XRT	X-ray topography