Some bars and restaurants in older buildings might request you dont put paper in the loo, but in modern buildings it's okay to flush.

I think you will find that many restaurants & bars where the toilets are situated downstairs will ask you deposit tiolet paper in a bin, this is because the sewage is pumped up to the main street sewer via a macerator pump and toilet paper will clogg & block the pump and stop it working. (What a lovely subject hehehe)
Cheers Jayjan

Hello all, this is not putting paper down the toilet but it did remind me of our first trip to France, we were staying in a small 2* hotel and only one young lady spoke English. My French was not very good I knew the basics on how to order a meal and a drink and so on, but when we ran out of toilet paper in our room I went down to the reception to get some more only to find a very old French lady who did not understand me even though I pretended to wipe my bottom, I can still see it now her looking at me like some kind of nutter and me with a red face.
If you do need to know what toilet paper is called in French it is, Papier Hygienique (papyay ee-zhay-neek) this will not do you much good in Portugal but it did give me a laugh when I saw the post.

Dave

..... very similar in Portuguese - papel higenico.