Well Known Text
 
WKT Version 2
COORDINATEOPERATION["AIOC95 depth to Caspian depth (1)",VERSION["AIOC95-Aze"],SOURCECRS[VERTCRS["AIOC95 depth",BASEVERTCRS["AIOC95 height",VDATUM["AIOC 1995",ID["EPSG",5133]],ID["EPSG",5797]],DERIVINGCONVERSION["Height <> Depth Conversion",METHOD["Height Depth Reversal",ID["EPSG",1068]],ID["EPSG",7812]],CS[vertical,1,ID["EPSG",6498]],AXIS["Depth (D)",down],LENGTHUNIT["metre",1,ID["EPSG",9001]],ID["EPSG",5734]]],TARGETCRS[VERTCRS["Caspian depth",BASEVERTCRS["Caspian height",VDATUM["Caspian Sea",ID["EPSG",5106]],ID["EPSG",5611]],DERIVINGCONVERSION["Height <> Depth Conversion",METHOD["Height Depth Reversal",ID["EPSG",1068]],ID["EPSG",7812]],CS[vertical,1,ID["EPSG",6498]],AXIS["Depth (D)",down],LENGTHUNIT["metre",1,ID["EPSG",9001]],ID["EPSG",5706]]],METHOD["Vertical Offset",ID["EPSG",9616]],PARAMETER["Vertical Offset",-1.7,LENGTHUNIT["metre",1,ID["EPSG",9001]],ID["EPSG",8603]],OPERATIONACCURACY[0],ID["EPSG",5403]]