From c594a32e814e7ec7ee3becdf2ddb4885bb885970 Mon Sep 17 00:00:00 2001
From: Natalia Mokeeva <natalia.mokeeva.de@gmail.com>
Date: Tue, 20 Jun 2023 22:52:09 +0200
Subject: [PATCH] DOC: point out that only period aliases are valid for Period
 method asfreq

---
 pandas/_libs/tslibs/period.pyx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pandas/_libs/tslibs/period.pyx b/pandas/_libs/tslibs/period.pyx
index e954ec9bccd9e..2ec0649110948 100644
--- a/pandas/_libs/tslibs/period.pyx
+++ b/pandas/_libs/tslibs/period.pyx
@@ -1917,7 +1917,8 @@ cdef class _Period(PeriodMixin):
         Parameters
         ----------
         freq : str, BaseOffset
-            The desired frequency.
+            The desired frequency. If passing a `str`, it needs to be a
+            valid :ref:`period alias <timeseries.period_aliases>`.
         how : {'E', 'S', 'end', 'start'}, default 'end'
             Start or end of the timespan.