@Override
	public void apply(ImportStateCache importState, RelocationState relocState, 
			ContainerHeader header, Program program, MessageLog log, TaskMonitor monitor) {

		List<ImportedSymbol> importedSymbols = header.getLoader().getImportedSymbols();

		switch (subopcode) {
			case RelocByIndexGroup.kPEFRelocSmByImport: {
				ImportedSymbol importedSymbol = importedSymbols.get(index);
				ImportedLibrary library = header.getLoader().findLibrary(index);
				String importedSymbolName = SymbolUtilities.replaceInvalidChars(importedSymbol.getName(), true);
				Symbol symbol = importState.getSymbol(importedSymbolName, library);
				relocState.relocateMemoryAt(relocState.getRelocationAddress(), 
											(int)symbol.getAddress().getOffset(), log);
				relocState.incrementRelocationAddress(4);
				relocState.setImportIndex(index + 1);
				break;
			}
			case RelocByIndexGroup.kPEFRelocSmSetSectC: {
				SectionHeader sectC = header.getSections().get(index);
				MemoryBlock blockC = importState.getMemoryBlockForSection(sectC);
				relocState.setSectionC(blockC.getStart());
				break;
			}
			case RelocByIndexGroup.kPEFRelocSmSetSectD: {
				SectionHeader sectD = header.getSections().get(index);
				MemoryBlock blockD = importState.getMemoryBlockForSection(sectD);
				relocState.setSectionD(blockD.getStart());
				break;
			}
			case RelocByIndexGroup.kPEFRelocSmBySection: {
				SectionHeader sect = header.getSections().get(index);
				MemoryBlock block = importState.getMemoryBlockForSection(sect);
				relocState.relocateMemoryAt(relocState.getRelocationAddress(), 
											(int)block.getStart().getOffset(), log);
				break;
			}
			default: {
				log.appendMsg("Unsupported RelocByIndexGroup subopcode: "+subopcode);
				break;
			}
		}
	}
This "RelocSmBySection" (SECN) instruction adds the address of the instantiated 
section specified by <code>index</code> to the word 
pointed to by <code>relocAddress</code>. After
execution, <code>relocAddress</code> points to just 
past the modified word.
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/pef/RelocByIndexGroup.java