diff --git a/jquantsapi/client.py b/jquantsapi/client.py
index 3112dfe..34475d9 100644
--- a/jquantsapi/client.py
+++ b/jquantsapi/client.py
@@ -622,7 +622,7 @@ def _get_prices_prices_am_raw(
 
         Args:
             code: issue code (e.g. 27800 or 2780)
-                If a 4-digit issue code is specified, only the data of common stock will be obtained
+                If a 4-character issue code is specified, only the data of common stock will be obtained
                 for the issue on which both common and preferred stocks are listed.
             pagination_key: ページングキー
 
@@ -648,7 +648,7 @@ def get_prices_prices_am(
 
         Args:
             code: issue code (e.g. 27800 or 2780)
-                If a 4-digit issue code is specified, only the data of common stock will be obtained
+                If a 4-character issue code is specified, only the data of common stock will be obtained
                 for the issue on which both common and preferred stocks are listed.
         Returns: pd.DataFrame: the morning session's OHLC data
         """
@@ -761,7 +761,7 @@ def _get_markets_weekly_margin_interest_raw(
 
         Args:
             code: issue code (e.g. 27800 or 2780)
-                If a 4-digit issue code is specified, only the data of common stock will be obtained
+                If a 4-character issue code is specified, only the data of common stock will be obtained
                 for the issue on which both common and preferred stocks are listed.
             from_yyyymmdd: starting point of data period (e.g. 20210901 or 2021-09-01)
             to_yyyymmdd: end point of data period (e.g. 20210907 or 2021-09-07)
@@ -799,7 +799,7 @@ def get_markets_weekly_margin_interest(
 
         Args:
             code: issue code (e.g. 27800 or 2780)
-                If a 4-digit issue code is specified, only the data of common stock will be obtained
+                If a 4-character issue code is specified, only the data of common stock will be obtained
                 for the issue on which both common and preferred stocks are listed.
             from_yyyymmdd: starting point of data period (e.g. 20210901 or 2021-09-01)
             to_yyyymmdd: end point of data period (e.g. 20210907 or 2021-09-07)
@@ -992,7 +992,7 @@ def _get_markets_breakdown_raw(
 
         Args:
             code: issue code (e.g. 27800 or 2780)
-                If a 4-digit issue code is specified, only the data of common stock will be obtained
+                If a 4-character issue code is specified, only the data of common stock will be obtained
                 for the issue on which both common and preferred stocks are listed.
             from_yyyymmdd: starting point of data period (e.g. 20210901 or 2021-09-01)
             to_yyyymmdd: end point of data period (e.g. 20210907 or 2021-09-07)
@@ -1030,7 +1030,7 @@ def get_markets_breakdown(
 
         Args:
             code: issue code (e.g. 27800 or 2780)
-                If a 4-digit issue code is specified, only the data of common stock will be obtained
+                If a 4-character issue code is specified, only the data of common stock will be obtained
                 for the issue on which both common and preferred stocks are listed.
             from_yyyymmdd: starting point of data period (e.g. 20210901 or 2021-09-01)
             to_yyyymmdd: end point of data period (e.g. 20210907 or 2021-09-07)
@@ -1523,7 +1523,7 @@ def _get_fins_dividend_raw(
 
         Args:
             code: issue code (e.g. 27800 or 2780)
-                If a 4-digit issue code is specified, only the data of common stock will be obtained
+                If a 4-character issue code is specified, only the data of common stock will be obtained
                 for the issue on which both common and preferred stocks are listed.
             from_yyyymmdd: starting point of data period (e.g. 20210901 or 2021-09-01)
             to_yyyymmdd: end point of data period (e.g. 20210907 or 2021-09-07)
@@ -1561,7 +1561,7 @@ def get_fins_dividend(
 
         Args:
             code: issue code (e.g. 27800 or 2780)
-                If a 4-digit issue code is specified, only the data of common stock will be obtained
+                If a 4-character issue code is specified, only the data of common stock will be obtained
                 for the issue on which both common and preferred stocks are listed.
             from_yyyymmdd: starting point of data period (e.g. 20210901 or 2021-09-01)
             to_yyyymmdd: end point of data period (e.g. 20210907 or 2021-09-07)