Azure Table Storage RowKey restricted Character Patterns?
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Are there restricted character patterns within Azure TableStorage RowKeys?  I've not been able to find any documented via numerous searches.  However, I'm getting behavior that implies such in some performance testing.

I've got some odd behavior with RowKeys consisting on random characters (the test driver does prevent the restricted characters (/ \ # ?) plus blocking single quotes from occurring in the RowKey).  The result is I've got a RowKey that will insert fine into the table, but cannot be queried (the result is InvalidInput). For example:

RowKey: 9}5O0J=5Z,4,D,{!IKPE,~M]%54+9G0ZQ&G34!G+

Attempting to query by this RowKwy (equality) will result in an error (both within our app, using Azure Storage Explorer, and Cloud Storage Studio 2).  I took a look at the request being sent via Fiddler:

GET /foo()?$filter=RowKey%20eq%20'9%7D5O0J=5Z,4,D,%7B!IKPE,~M%5D%54+9G0ZQ&G34!G+' HTTP/1.1

It appears the %54 in the RowKey is not escaped in the filter.  Interestingly, I get similar behavior for batch requests to table storage with URIs in the batch XML that include this RowKey.  I've also seen similar behavior for RowKeys with embedded double quotes, though I have not isolated that pattern yet.

Has anyone co me across this behavior?  I can easily restrict additional characters from occurring in RowKeys, but would really like to know the 'rules'.