The next piece of information you need to communicate is whether you are buying or selling. As market conditions change you may need to cancel the current order you are working. Making a slashing motion across your throat means cancel my bid or offer. You just made your first trade. This is an example of a multi-part ticket before being filled out by a phone clerk.
All parties keep a copy during each step of the execution.
At the market means to buy or sell at the current market price. June September and December are M, U and Z, respectively. You have bought five March Swiss francs at a price of 8350. The broker who sold them to your filling broker was ABC trading through clearing firm number 000. Your filling broker was GHI trading through clearing firm number 456.