diff --git a/Why-are-we-using-%60gitea.com%2FBoYanZh%2Fcheckout%60%3F.md b/Why-are-we-using-%60gitea.com%2FBoYanZh%2Fcheckout%60%3F.md
new file mode 100644
index 0000000..f23f69a
--- /dev/null
+++ b/Why-are-we-using-%60gitea.com%2FBoYanZh%2Fcheckout%60%3F.md
@@ -0,0 +1,3 @@
+1. `act_runner` only supports URL with format `${host}/${owner}/${name}`, `${host}/git/${owner}/${name}` does not work.
+2. By default, `actions/checkout` also only supports URL with format `${host}/${owner}/${name}`.
+3. `gitea.com/BoYanZh/checkout` is modified, which hardcodes ssh port to clone the repo in `act_runner`.
\ No newline at end of file