With the festive season approaching, the central bank yesterday warned the public to be on the lookout for high quality counterfeit 100-yuan banknotes.

Though mostly counterfeit 100-yuan ($14) notes are not too hard to make out, people should be careful as cash transactions during Spring Festival are high, the bank said.

Recent media reports said that 100-yuan notes, starting with the numbers "HD90,” are fake, but their quality is so high that even cash detectors cannot make them out. The central bank denied the reports yesterday.

On January 2, the Guangzhou-based Information Times reported that a convenience store owner in Dongguan, Guangdong province received 15 100-yuan notes starting with the figures HD90, and all of them turned out to be fake.

The Chongqing Morning Post reported yesterday that the HD90 counterfeit notes have been found in 10 provincial regions.

However, the People's Bank of China confirmed that some fake notes, starting with "HD9026," with magnetic strips and characters similar to Braille, could fail "low quality cash detectors," but can be easily made out with the naked eye.

"Even ordinary people can make out from their quality, watermarks and oil," it said.

The central bank issued a statement saying the HD90 fake notes were also found in 2007, but they now come with "far improved quality and features" similar to the original notes.

In 2007, Guangdong police unearthed a fake notes factory in Jieyang and found a large number of notes starting with the numbers HD90.

"We do not know if there is any other source of such notes,” the statement said.

Questions:

1. What numbers do the counterfeit 100-yuan bank notes start with?

2. What features are found on some fake notes starting with “HD9026”?

3. Where was a fake notes factory unearthed in 2007?

Answers:

1. HD90.

2. Magnetic strips and characters similar to Braille.

3. Jieyang.