Add 'scraper -> UNKNOWN company' warning to the README.

diff --git a/README b/README
index 8063787b6e169b9d950928c0666541e3968cb98b..cb2a4bbf86720c544ea9a3f7d472e2b7e54c5674 100644 (file)
--- a/README
+++ b/README
@@ -59,6 +59,11 @@ transaction data automatically.  To get you started, I've written
 
 __ NASDAQ_
 
+If the scraper doesn't extract company names (`nasdaq.py` does not),
+it's probably a good idea to add the relevant `Company` and `Ticker`
+to the database before running the scraper.  Otherwise you may get
+tickers from several echanges all pointing to the company `UNKNOWN`.
+
 Hacking
 =======