diff --git a/src/zcl_excel_converter.clas.abap b/src/zcl_excel_converter.clas.abap
index 128420e..fa031c6 100644
--- a/src/zcl_excel_converter.clas.abap
+++ b/src/zcl_excel_converter.clas.abap
@@ -104,11 +104,11 @@ CLASS zcl_excel_converter DEFINITION
     DATA wt_sort_values TYPE tt_sort_values .
     DATA wt_subtotal_rows TYPE tt_subtotal_rows .
     DATA wt_styles TYPE tt_styles .
-    CONSTANTS c_type_hdr TYPE char1 VALUE 'H'.              "#EC NOTEXT
-    CONSTANTS c_type_str TYPE char1 VALUE 'P'.              "#EC NOTEXT
-    CONSTANTS c_type_nor TYPE char1 VALUE 'N'.              "#EC NOTEXT
-    CONSTANTS c_type_sub TYPE char1 VALUE 'S'.              "#EC NOTEXT
-    CONSTANTS c_type_tot TYPE char1 VALUE 'T'.              "#EC NOTEXT
+    CONSTANTS c_type_hdr TYPE c VALUE 'H'.              "#EC NOTEXT
+    CONSTANTS c_type_str TYPE c VALUE 'P'.              "#EC NOTEXT
+    CONSTANTS c_type_nor TYPE c VALUE 'N'.              "#EC NOTEXT
+    CONSTANTS c_type_sub TYPE c VALUE 'S'.              "#EC NOTEXT
+    CONSTANTS c_type_tot TYPE c VALUE 'T'.              "#EC NOTEXT
     DATA wt_color_styles TYPE tt_color_styles .
     CLASS-DATA ws_option TYPE zexcel_s_converter_option .
     CLASS-DATA ws_indx TYPE indx .
@@ -215,7 +215,7 @@ CLASS zcl_excel_converter DEFINITION
         VALUE(r_function_number) TYPE int1 .
     METHODS get_style
       IMPORTING
-        !i_type        TYPE char1
+        !i_type        TYPE ty_style_type
         !i_alignment   TYPE zexcel_alignment DEFAULT space
         !i_inttype     TYPE inttype DEFAULT space
         !i_decimals    TYPE int1 DEFAULT 0
diff --git a/src/zcl_excel_converter.clas.locals_def.abap b/src/zcl_excel_converter.clas.locals_def.abap
index c1e3c47..8182f43 100644
--- a/src/zcl_excel_converter.clas.locals_def.abap
+++ b/src/zcl_excel_converter.clas.locals_def.abap
@@ -2,6 +2,8 @@
 *"* definitions, interfaces or data types) you need for method
 *"* implementation or private method's signature
 
+TYPES ty_style_type TYPE c LENGTH 1.
+
 TYPES:   BEGIN OF ts_alv_types,
            seoclass   TYPE seoclsname,
            clsname    TYPE seoclsname,
@@ -27,7 +29,7 @@ TYPES:   BEGIN OF ts_subtotal_rows,
          tt_subtotal_rows TYPE HASHED TABLE OF ts_subtotal_rows WITH UNIQUE KEY row_int.
 
 TYPES:   BEGIN OF ts_styles,
-            type         TYPE char1,
+            type         TYPE ty_style_type,
             alignment    TYPE zexcel_alignment,
             inttype      TYPE inttype,
             decimals     TYPE int1,
diff --git a/src/zcl_excel_drawing.clas.abap b/src/zcl_excel_drawing.clas.abap
index ea04fe1..be4c140 100644
--- a/src/zcl_excel_drawing.clas.abap
+++ b/src/zcl_excel_drawing.clas.abap
@@ -19,8 +19,6 @@ CLASS zcl_excel_drawing DEFINITION
     CONSTANTS c_graph_bars TYPE zexcel_graph_type VALUE 0.  "#EC NOTEXT
     DATA graph_type TYPE zexcel_graph_type .
     DATA title TYPE string VALUE 'image1.jpg'.              "#EC NOTEXT
-    DATA x_references TYPE char1 .
-    DATA y_references TYPE char1 .
     CONSTANTS type_image TYPE zexcel_drawing_type VALUE 'image'. "#EC NOTEXT
     CONSTANTS type_chart TYPE zexcel_drawing_type VALUE 'chart'. "#EC NOTEXT
     CONSTANTS anchor_absolute TYPE zexcel_drawing_anchor VALUE 'ABS'. "#EC NOTEXT
@@ -133,14 +131,14 @@ CLASS zcl_excel_drawing DEFINITION
     DATA type TYPE zexcel_drawing_type VALUE type_image. "#EC NOTEXT .  .  .  .  .  .  .  .  .  .  . " .
     DATA index TYPE string .
     DATA anchor TYPE zexcel_drawing_anchor VALUE anchor_one_cell. "#EC NOTEXT .  .  .  .  .  .  .  .  .  .  . " .
-    CONSTANTS c_media_source_www TYPE char1 VALUE 1.        "#EC NOTEXT
-    CONSTANTS c_media_source_xstring TYPE char1 VALUE 0.    "#EC NOTEXT
-    CONSTANTS c_media_source_mime TYPE char1 VALUE 2.       "#EC NOTEXT
+    CONSTANTS c_media_source_www TYPE c VALUE 1.        "#EC NOTEXT
+    CONSTANTS c_media_source_xstring TYPE c VALUE 0.    "#EC NOTEXT
+    CONSTANTS c_media_source_mime TYPE c VALUE 2.       "#EC NOTEXT
     DATA guid TYPE guid_16 .
     DATA media TYPE xstring .
     DATA media_key_www TYPE wwwdatatab .
     DATA media_name TYPE string .
-    DATA media_source TYPE char1 .
+    DATA media_source TYPE c .
     DATA media_type TYPE string .
     DATA io TYPE skwf_io .
     DATA from_loc TYPE zexcel_drawing_location .
diff --git a/src/zcl_excel_drawing.clas.xml b/src/zcl_excel_drawing.clas.xml
index 8ae6ba0..b5ef6a2 100644
--- a/src/zcl_excel_drawing.clas.xml
+++ b/src/zcl_excel_drawing.clas.xml
@@ -576,30 +576,6 @@
      <LANGU>E</LANGU>
      <DESCRIPT>Excel Drawing type</DESCRIPT>
     </SEOCOMPOTX>
-    <SEOCOMPOTX>
-     <CLSNAME>ZCL_EXCEL_DRAWING</CLSNAME>
-     <CMPNAME>X_REFERENCES</CMPNAME>
-     <LANGU>E</LANGU>
-     <DESCRIPT>Single-Character Indicator</DESCRIPT>
-    </SEOCOMPOTX>
-    <SEOCOMPOTX>
-     <CLSNAME>ZCL_EXCEL_DRAWING</CLSNAME>
-     <CMPNAME>X_REFERENCES</CMPNAME>
-     <LANGU>I</LANGU>
-     <DESCRIPT>Single-Character Indicator</DESCRIPT>
-    </SEOCOMPOTX>
-    <SEOCOMPOTX>
-     <CLSNAME>ZCL_EXCEL_DRAWING</CLSNAME>
-     <CMPNAME>Y_REFERENCES</CMPNAME>
-     <LANGU>E</LANGU>
-     <DESCRIPT>Single-Character Indicator</DESCRIPT>
-    </SEOCOMPOTX>
-    <SEOCOMPOTX>
-     <CLSNAME>ZCL_EXCEL_DRAWING</CLSNAME>
-     <CMPNAME>Y_REFERENCES</CMPNAME>
-     <LANGU>I</LANGU>
-     <DESCRIPT>Single-Character Indicator</DESCRIPT>
-    </SEOCOMPOTX>
    </DESCRIPTIONS>
   </asx:values>
  </asx:abap>
diff --git a/src/zcl_excel_writer_huge_file.clas.abap b/src/zcl_excel_writer_huge_file.clas.abap
index 2c17a31..b8bce81 100644
--- a/src/zcl_excel_writer_huge_file.clas.abap
+++ b/src/zcl_excel_writer_huge_file.clas.abap
@@ -51,7 +51,7 @@ CLASS zcl_excel_writer_huge_file IMPLEMENTATION.
       END OF ts_root.
 
     DATA:
-      lv_last_allowed_char TYPE char1,
+      lv_last_allowed_char TYPE c,
       lv_invalid           TYPE string.
 
     DATA:
@@ -69,6 +69,7 @@ CLASS zcl_excel_writer_huge_file IMPLEMENTATION.
 
 **********************************************************************
 * STEP 0: Build Regex for invalid characters
+" uccpi returns 2 chars but for this specific input 1 char is enough
     CASE cl_abap_char_utilities=>charsize.
       WHEN 1.lv_last_allowed_char = cl_abap_conv_in_ce=>uccpi( 255 ).  " FF     in non-Unicode
       WHEN 2.lv_last_allowed_char = cl_abap_conv_in_ce=>uccpi( 65533 )." FFFD   in Unicode