A visa can be for a single entry, double entry (two entries – for example allowing a visit to a neighboring country such as Kazakhstan or China as part of the visit), or multiple entry.
When the visa takes the form of rubber stamp imprint placed on a page – a single entry visa carries a single circular stamp, whereas double and multiple entry visas are validated by two circular stamps. A new system has been introduced using stickers which are placed on an empty page. These are stamped only once.
Dates: The visa carries three dates:
the date of issue,
the date from which the visa is valid for entry to the country (which has to be within six months of the date of issue), and
the date until which the visa is valid.
It is not necessary to enter and leave the country on the exact dates that are specied, ("from" and "until") … they specify the date between which the visa is valid.
Inviting organization: Where an invitation is required – the name of the inviting party is indicated here. For example, the name of our company – it may be written in Russian. (It is here, because the inviting organization accepts certain responsibilities and obligations in respect to the visitor).
There will also be a signature of the consular officer issuing the visa, and a stamp – or else the visa is not valid.