Texas Hold ‘Em Variation of Rules

For games in the United States and other countries where the official language is English, then only English is allowed to be spoken at the table.
Poker is a universal game, but this rule is in place to prevent collusion by other players who speak another language.  Frequently players who speak other languages will try to gain an edge by communicating what cards they hold to compatriots at the table.
In another attempt to curb cheating practices, many land-based casinos have banned the use of cell phone or other communication devices while at the table.  Players are asked to step away from the table before placing or receiving a call.  Additionally, many casinos ask players not to leave shiny or highly reflective items on the felt as they could be used for cheating purposes.

Another rule that is common, but sometimes not enforced well is that players should refrain from talking about a hand while it is in progress.  Table talk of this nature could influence another player's decision and is generally discouraged.
Players are advised to keep their higher denomination chips towards the front of their stack so other players can be aware of how much money is in play.

This also prevents players from hiding bigger chips when moving all-in, thus distorting the amount of the bet to be called.  In other chip-related rules, many casinos ask that players exchange chips only with the dealer to prevent possible collusion and to prevent players from taking chips off of the table and out of play.