diff --git a/Analyser/Static/Acorn/StaticAnalyser.cpp b/Analyser/Static/Acorn/StaticAnalyser.cpp
index b3cc7f52c..ac4407ad4 100644
--- a/Analyser/Static/Acorn/StaticAnalyser.cpp
+++ b/Analyser/Static/Acorn/StaticAnalyser.cpp
@@ -108,15 +108,20 @@ Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &me
 		dfs_catalogue = GetDFSCatalogue(disk);
 		if(dfs_catalogue == nullptr) adfs_catalogue = GetADFSCatalogue(disk);
 		if(dfs_catalogue || adfs_catalogue) {
+			// Accept the disk and determine whether DFS or ADFS ROMs are implied.
 			target->media.disks = media.disks;
-			target->has_dfs = !!dfs_catalogue;
-			target->has_adfs = !!adfs_catalogue;
+			target->has_dfs = bool(dfs_catalogue);
+			target->has_adfs = bool(adfs_catalogue);
 
+			// Check whether a simple shift+break will do for loading this disk.
 			Catalogue::BootOption bootOption = (dfs_catalogue ?: adfs_catalogue)->bootOption;
-			if(bootOption != Catalogue::BootOption::None)
+			if(bootOption != Catalogue::BootOption::None) {
 				target->should_shift_restart = true;
-			else
+			} else {
 				target->loading_command = "*CAT\n";
+			}
+
+			// TODO: check whether adding the AP6 ROM is justified.
 		}
 	}
 
diff --git a/ROMImages/Electron/readme.txt b/ROMImages/Electron/readme.txt
index accfc031e..995145ee9 100644
--- a/ROMImages/Electron/readme.txt
+++ b/ROMImages/Electron/readme.txt
@@ -4,13 +4,41 @@ Expected files:
 
 basic.rom
 os.rom
-plus1.rom
-DFS-1770-2.20.rom
-ADFS-E00_1.rom
+DFS-1770-2.20.rom	— used only if the user opens a DFS disk image
+ADFS-E00_1.rom		— used only if the user opens an ADFS disk image
 ADFS-E00_2.rom
+AP6v133.rom			— used only if the user opens a disk image that makes use of any of the commands given below.
 
-Likely to be desired in the future:
+Possibly to be desired in the future:
+* adfs.rom
+* ElectronExpansionRomPresAP2-v1.23.rom
+* os300.rom
 
-adfs.rom
-ElectronExpansionRomPresAP2-v1.23.rom
-os300.rom
+Commands that trigger a request for the AP6v133 ROM:
+* *AQRPAGE
+* *BUILD
+* *DUMP
+* *FORMAT
+* *INSERT
+* *LANG
+* *LIST
+* *LOADROM
+* *LOCK
+* *LROMS
+* *RLOAD
+* *ROMS
+* *RSAVE
+* *SAVEROM
+* *SRLOAD
+* *SRLOCK
+* *SRPAGE
+* *SRSAVE
+* *SRUNLOCK
+* *SRWIPE
+* *TUBE
+* *TYPE
+* *UNLOCK
+* *UNPLUG
+* *UROMS
+* *VERIFY
+* *ZERO
\ No newline at end of file