Index: trunk/src/libcschem/concrete.h
===================================================================
--- trunk/src/libcschem/concrete.h	(revision 10249)
+++ trunk/src/libcschem/concrete.h	(revision 10250)
@@ -2,7 +2,7 @@
  *                            COPYRIGHT
  *
  *  cschem - modular/flexible schematics editor - libcschem (core library)
- *  Copyright (C) 2018, 2022 Tibor 'Igor2' Palinkas
+ *  Copyright (C) 2018, 2022, 2024 Tibor 'Igor2' Palinkas
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
@@ -197,7 +197,8 @@
 	CSCH_SHTY_unknown,
 	CSCH_SHTY_UNLISTED, /* not explicitly listen in the project file, just happens to be in the same dir */
 	CSCH_SHTY_ROOT,     /* explicitly listed in project file as a root sheet */
-	CSCH_SHTY_AUX       /* explicitly listed in project file as an aux sheet */
+	CSCH_SHTY_AUX,      /* explicitly listed in project file as an aux sheet */
+	CSCH_SHTY_EXTERNAL  /* not explicitly listen in the project file, loaded during compilation, for hierarchy */
 } csch_sheet_type_t;
 
 struct csch_sheet_s {
Index: trunk/src/libcschem/hierarchy.h
===================================================================
--- trunk/src/libcschem/hierarchy.h	(revision 10249)
+++ trunk/src/libcschem/hierarchy.h	(revision 10250)
@@ -49,7 +49,7 @@
 /* Return 1 if sheet:sym is a subsheet reference, 0 otherwise. If a subsheet ref,
    look up the child subsheet and load *child_out with it. If a sheet needs to
    be loaded from the hlibrary, it is added to the in-memory project; normally
-   this means adding it as an unlisted file. If add_to_prj_as_aux is
+   this means adding it as an external file. If add_to_prj_as_aux is
    not 0, the new sheet is added to the project file as an aux sheet.
    Returns -1 on error (lookup failure) */
 int csch_hier_find_sym_child(const csch_sheet_t *sheet, csch_cgrp_t *sym, csch_sheet_t **child_out, int add_to_prj_as_aux);
Index: trunk/src/plugins/gui/sheetsel.c
===================================================================
--- trunk/src/plugins/gui/sheetsel.c	(revision 10249)
+++ trunk/src/plugins/gui/sheetsel.c	(revision 10250)
@@ -2,9 +2,9 @@
  *                            COPYRIGHT
  *
  *  cschem - modular/flexible schematics editor - GUI
- *  Copyright (C) 2022,2023 Tibor 'Igor2' Palinkas
+ *  Copyright (C) 2022,2023,2024 Tibor 'Igor2' Palinkas
  *
- *  (Supported by NLnet NGI0 PET Fund in 2022, Entrust in 2023)
+ *  (Supported by NLnet NGI0 PET Fund in 2022, Entrust in 2023,2024)
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -62,6 +62,7 @@
 	" [R] root sheet (directly compiled)\n"
 	" [a] aux sheet (referenced from hierarchy)\n"
 	" [u] unlisted sheet (in the same dir)\n"
+	" [E] external (unlisted, loaded for hierarchy)\n"
 	" [?] unknown/undecided sheet state\n";
 
 typedef struct sheetsel_ctx_s sheetsel_ctx_t;
@@ -80,6 +81,7 @@
 		case CSCH_SHTY_AUX:      return " [a]";
 		case CSCH_SHTY_ROOT:     return " [R]";
 		case CSCH_SHTY_UNLISTED: return " [u]";
+		case CSCH_SHTY_EXTERNAL: return " [E]";
 	}
 	return " [??]";
 }