diff --git a/scapy/layers/all.py b/scapy/layers/all.py
index 9060916fe9113f6ffe1e3fc009ab097073b036b4..7e593e7f878f0cf212efbbc9323df4d56135e0c2 100644
--- a/scapy/layers/all.py
+++ b/scapy/layers/all.py
@@ -18,6 +18,9 @@ __all__ = []
 
 
 def _validate_local(x):
+    """Returns whether or not a variable should be imported.
+    Will return False for any default modules (sys), or if
+    they are detected as private vars (starting with a _)"""
     global ignored
     return x[0] != "_" and not x in ignored
 
diff --git a/scapy/main.py b/scapy/main.py
index 2f57dcae606c3558187c7d520f36c45b6a82573d..9066667a75b21322f3609fdec76177991f058e31 100644
--- a/scapy/main.py
+++ b/scapy/main.py
@@ -38,6 +38,9 @@ def _read_config_file(cf):
         log_loading.exception("Error during evaluation of config file [%s]" % cf)
         
 def _validate_local(x):
+    """Returns whether or not a variable should be imported.
+    Will return False for any default modules (sys), or if
+    they are detected as private vars (starting with a _)"""
     global ignored
     return x[0] != "_" and not x in ignored