Sunderland fans are again banned from wearing "smog" masks and chemical outfits at next week's crucial derby with relegation rivals Middlesbrough.
Anyone flouting the advice will be denied entry to next Wednesday's Premier League game or ejected if they put the items on once inside the Riverside Stadium.
The restriction is contained within lengthy safety advice issued by Sunderland Football Club after discussions with the home side and both Cleveland and Northumbria police forces.
It follows previous encounters in which Sunderland fans have worn such clothing to poke fun at their neighbours' links to the chemical industry.
A club statement said: "Any person wearing overalls and dust masks ('smog suits') will be refused admission or, if worn thereafter, will be removed from the stadium."
With the Black Cats providing free coach travel to and from Teesside, supporters are strongly urged to take up the offer as it affords the safest and easiest method of transport on April 26.
The statement continues: "Concourse facilities, offering food and drink to purchase, including alcohol, will be open in the east stand of the Stadium of Light from 4pm on Wednesday afternoon.
"The coaches will begin boarding from the green car park, outside the ticket office, at 5pm and will then depart under escort for Middlesbrough promptly at 5.30pm. On arrival at the Riverside Stadium, Sunderland supporters will be guided directly to the away turnstiles.
"Only those coaches forming part of the official escort will be allowed to park at the stadium and will be located adjacent to the visitors’ turnstiles and exits.
"No further vehicles can now be accommodated, therefore any additional coaches or minibuses travelling independently must secure their own parking arrangements before travelling to the area, as they will not be permitted to park at the stadium.
Supporters still travelling independently are strongly advised to plan ahead, allowing extra time for their journey in order to cope with peak-time traffic and to find parking spots.
The sold-out away section has also changed since Sunderland's last visit more than five years and is now in the south east corner of the stadium to the right of where it used to be.
Visiting fans’ turnstiles 53-61 will open at 6.30pm with the match beginning at 7.45pm.
Supporters are also reminded that smoking is banned in the stadium and the use of electronic cigarettes, or similar, is not permitted although an external smoking area will be available at exit 41 during half-time.
Following final whistle, visiting supporters will be asked to remain inside the stadium to allow the home crowds to leave before making their own way home or moving onto their coaches.
During this time, supporters will be able to purchase refreshments, watch the TVs and use the toilet facilities.
The statement adds: "Alcoholic and soft drinks will be available to purchase from the stadium concourse, pre-match, at half-time and at the end of the game to allow visiting supporters to wait in comfort as the crowds disperse."