documented some fields thx to PMDe

asm/code_8012A18.s

@@ -168492,7 +168492,7 @@ sub_8065FB4:
 	ldr r1, _08065FE8
 	adds r0, r1
 	ldrb r0, [r0]
-	bl sub_8090148
+	bl GetRecruitable
 	lsls r0, 24
 	cmp r0, 0
 	bne _08065FF0
@@ -187757,7 +187757,7 @@ _0806F6F0:
 	ldr r2, _0806F834
 	adds r0, r3, r2
 	ldrb r0, [r0]
-	bl sub_8090148
+	bl GetRecruitable
 	lsls r0, 24
 	cmp r0, 0
 	bne _0806F702

include/dungeon.h

@@ -11,7 +11,7 @@ struct Dungeon
 {
     u8 stairDirection;
     u8 unk1;
-    u8 unk2;
+    u8 isRecruitable;
     s8 unk3;
     u8 maxItemCount;
     u8 maxPartySize;
@@ -20,8 +20,8 @@ struct Dungeon
     u8 unk8;
     u8 unk9;
     u8 saveBeforeEntering;  //whether to quicksave or not before entering
-    u8 unkB;
-    s16 unkC;
+    u8 unkB; // Apparently is a HM mask (Fly, Dive, Waterfall, Surf, Water)
+    s16 timer;
     s16 unkE;
 };
 

src/dungeon.c

@@ -18,7 +18,7 @@ u8 GetStairDirection(u8 dungeon)
 
 s16 GetUnkC(u8 dungeon)
 {
-    return gDungeons[dungeon].unkC;
+    return gDungeons[dungeon].timer;
 }
 
 u8 GetSaveBeforeEntering(u8 dungeon)
@@ -51,9 +51,9 @@ s8 GetUnk3(u8 dungeon)
     return gDungeons[dungeon].unk3;
 }
 
-u8 sub_8090148(u8 dungeon)
+u8 GetRecruitable(u8 dungeon)
 {
-    return gDungeons[dungeon].unk2;
+    return gDungeons[dungeon].isRecruitable;
 }
 
 u8 sub_8090158(u8 dungeon)