diff --git a/CHANGELOG.md b/CHANGELOG.md
index 87d9df8..c67f673 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@
 ## 1.4.5
 * drop Python3.9 support
 * fix: Setting field type by `--type` suppresses the auto-detection.
+* fix: split by CIDR
+* fix: single value regex preview wizzard
 
 ## 1.4.4 (2023-05-26)
 * fix: OTRS sending with no attachment forwarded
diff --git a/README.md b/README.md
index fe9ffcc..7a32482 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ Any input is accepted:
     6) **Aggregate** (count grouped by a column, sum...)
     7) **Merge** (join other file)
 
-Python3.7+ required (older releases support 3.6).
+Python3.10+ required (older releases support up to 3.6).
 
 # Table of contents
 * [Usage](#usage)
@@ -673,10 +673,11 @@ heLLo
 
 Specify source
 ```bash
-# start adding a new reg column wizzard that will take plaintext "aGVsbG8=" as input
+# start adding a new reg column wizzard that will take plaintext from auto-detected base64 "aGVsbG8=" as input
 $ convey aGVsbG8= -f reg,plaintext
-# specifying plaintext as a source type will prevent implicit convertion from base64
-$ convey aGVsbG8= -f reg_s,plaintext,"[A-Z]","!" -H  # substitute uppercase letters with '!'
+# specifying plaintext as a source type (and not as a column) will prevent implicit conversion from base64
+# Note the 1 that specifies the (first and only) column.
+$ convey aGVsbG8= -f reg_s,1,plaintext,"[A-Z]","!" -H  # substitute uppercase letters with '!'
 a!!sb!8=
 ```
 
diff --git a/convey/controller.py b/convey/controller.py
index 2678a5a..1ea117e 100644
--- a/convey/controller.py
+++ b/convey/controller.py
@@ -403,7 +403,7 @@ def change_dialect(s, s2):
             exit()
         return ac
 
-    def run_menu(self, ac):
+    def run_menu(self, ac: ActionController):
         # main menu
         start_debugger = False
         session = None
diff --git a/convey/parser.py b/convey/parser.py
index fc0959d..32f4c9a 100644
--- a/convey/parser.py
+++ b/convey/parser.py
@@ -148,6 +148,7 @@ def prepare(self):
             print("Empty contents.")
             exit()
         self.prepare_target_file()
+        self.sample_parsed = [x for x in csv.reader(self.sample)]
 
         # check if we are parsing a single cell
         if self.stdin:
@@ -209,7 +210,6 @@ def join_quo(s):
                     return self
 
         # we are parsing a CSV file
-        self.sample_parsed = [x for x in csv.reader(self.sample)]
         self.informer.sout_info()
         try:
             # Dialog to obtain basic information about CSV - delimiter, header
@@ -277,7 +277,7 @@ def get_fields_autodetection(self, append_values=True):
         :type append_values: bool Append sample values to the informative result string.
         """
         fields = []
-        for col, field in enumerate(self.fields):
+        for _, field in enumerate(self.fields):
             s = ""
             if field.is_new:
                 s = f"computed from: {field.source_type}"
diff --git a/convey/processor.py b/convey/processor.py
index 7a36172..59fe8b6 100644
--- a/convey/processor.py
+++ b/convey/processor.py
@@ -358,9 +358,10 @@ def process_line(self, parser: Parser, line: List, settings: Settings, fields: U
                 chosen_fields = fields
 
             # determine location
-            if type(settings["split"]) == int:
-                # split ('/' is a forbidden char in linux file names)
-                location = fields[settings["split"]].replace("/", "-")
+            if type(settings["split"]) == int:  # split location:
+                # * '/' is a forbidden char in linux file names)
+                # * we cast to str as the field could contain an object (like IPRange for the 'cidr' type)
+                location = str(fields[settings["split"]]).replace("/", "-")
                 if not location:
                     parser.unknown_lines_count += 1
                     location = Config.UNKNOWN_NAME
@@ -429,10 +430,8 @@ def process_line(self, parser: Parser, line: List, settings: Settings, fields: U
             if self.descriptors_count >= self.descriptors_max:  # too many descriptors open, we have to close the least used
                 key = min(self.descriptorsStatsOpen, key=self.descriptorsStatsOpen.get)
                 self.descriptors[key][0].close()
-                # print("Closing", key, self.descriptorsStatsOpen[key])
                 del self.descriptorsStatsOpen[key]
                 self.descriptors_count -= 1
-            # print("Opening", location)
 
             if location == 2:  # this is a sign that we store raw data to stdout (not through a CSVWriter)
                 t = w = parser.external_stdout  # custom object simulate CSVWriter - it adopts .writerow and .close methods
diff --git a/convey/wizzard.py b/convey/wizzard.py
index 6b82a6e..f7ffbbf 100644
--- a/convey/wizzard.py
+++ b/convey/wizzard.py
@@ -17,8 +17,9 @@
 from pygments.token import Token
 from tabulate import tabulate
 
-from convey import PickInput
 from .config import Config, console_handler
+from .decorators import PickInput
+from .field import Field
 from .dialogue import Cancelled
 from .types import Type, Types
 
@@ -181,7 +182,7 @@ def validate(self, document):
 
 class Preview:
 
-    def __init__(self, source_field, source_type: "Type", target_type: "Type" = None):
+    def __init__(self, source_field: Field, source_type: Type, target_type: Type = None):
         self.source_field = source_field
         self.source_type = source_type
         self.target_type = target_type