diff --git a/.gitignore b/.gitignore
index 8321c7d2..16917890 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,5 @@ htmlcov/
 .cache/
 .pytest_cache/
 doc/auto_examples/*
-doc/generated/*
\ No newline at end of file
+doc/generated/*
+venv/
\ No newline at end of file
diff --git a/doc/supervised.rst b/doc/supervised.rst
index 1b1180e9..c6d8b68b 100644
--- a/doc/supervised.rst
+++ b/doc/supervised.rst
@@ -292,6 +292,11 @@ same class are not imposed to be close.
     lfda = LFDA(k=2, dim=2)
     lfda.fit(X, Y)
 
+.. note::
+    LDFA suffers from a problem called “sign indeterminacy”, which means the sign of the ``components`` and the output from transform depend on a random state. This is directly related to the calculation of eigenvectors in the algorithm. The same input ran in different times might lead to different transforms, but both valid.
+    
+    To work around this, fit instances of this class to data once, then keep the instance around to do transformations.
+
 .. topic:: References:
 
     .. [1] Sugiyama. `Dimensionality Reduction of Multimodal Labeled Data by Local