Venetian / Murano glass has been made and shipped world-wide for centuries. At first the glass techniques developed there were protected by the government of Venice by requiring all glass makers to remain on Murano for life. When Venetian control of maritime transportation was broken, glass artists were lured to other European countries, where they set up new glass houses that also produced glassware in the Murano style. Many of the Italian terms for these wares are still in use: millefiore, latticino, lattimo, etc.
Always a destination on the Grand Tour, Venice/Murano enjoyed renewed life as a glass manufacturing center during the Twentieth Century. Murano exported vast quantities of glass figures and glass table-top items. In addition, Murano beads have always be carefully preserved by their owners due to their beauty and value.
Due to continued demand for Murano-style glass collectibles and beads, similar items are manufactured in India and China. Therefore, to collect Murano glass, one has to be careful and educated. Paper stickers are used to identify recently made items, but the unscrupulous can transfer these to non-Murano pieces and get better prices, so the sticker is not a guarantee.
The true mark of Murano glass is in the style and quality of the product. An educated eye and the many books on Murano glass can help you decide what will fit into your collection. You should also use reputable dealers if you intend to spend a lot of money on any particular item. An listen to the little voice in the back of your head.
Even in Venice, be sure to buy from established business, as it is not inconceivable that imported, less valuable items will be on sale.
The other tactic to take, and one I personally use, is to ignore the “Murano” attribution and buy items you like sufficiently to pay the price. Then the origin of the item is a moot point to you. Over time, you may change your mind about some of the items you have purchased, but they can be sold and replaced with examples you like more.
I realize that this is not particularly helpful. I wish I could point at something concrete and say “If this is present, the glass is from Murano.”, but I can’t. Due to the time span glass has been produced there, the desirability of the glass at all times and the volume of imitators, there can be few guarantees beyond personal purchase from a reputable business in Venice. And as fun as that would be, few of us can afford it. So purchase Murano glass with the reservation that it may prove to be from another source.