Changing Marc tag 050 field group from c to y

[Wan Lye Tim <wanlt@xxxxxxxxxx>]

We have been using Marc tag 090 for local call number.  Recently we started
to download/create Marc tag 050 in our bibliographic record.  However, the
WebOPAC is now displaying the call no. from tag 050 instead of tag 090.  To
overcome this, we are changing the field group for Marc 050 from group "c"
to group "y".  We are keeping tag 050 only for historical purpose and do
not mind it not being indexed.  We are not ready to carry out a
re-indexing.

1    Has anyone who has changed the field group for tag 050 to "y"
     encountered any negative effect?

2    Is there an alternative way to ensure display of tag 090 as priority
     wrt tag 050 and other tag 09x?

Thank you for your help.

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
---