There is really not a standard. I have a standard that I used to use on my web site that I will share, the standard is not one I devised, it was around and used in most card rooms. It is a notation for describing game limits, and tournament levels. With the advent of online poker people started describing games in different ways and what standard there was got muddled. Also people tend to assume that everyone is talking about no limit hold'em, which is essentially a bad assumption.
I would write it NL 200/400/75
For a limit tournament, Limit 200/400/75 is not the blind size but the size of the limit, the blinds are 100/200
You can omit the NL or Limit in the line item if the header says something like No Limit Hold'em Tournament.
The notation I used was mostly for a way to describe cash games. NL 200/400/75 would not be clear describing a cash game with an ante, it would mean there were three blinds. No limit used to frequently be played with the third blind on the button. if the 75 is an ante it should be preceded with an "A", 200/400/A75, otherwise it would be assumed the 75 was a button blind. If I was advocating a standard for NL notation it would be 200/400/75 means blinds of 200,400, 75 and 200/400-75 would mean 200 and 400 blinds with a 75 ante.
With the notation a back slash denoted blinds and fixed limits. A big blind limit game like ten twenty limit, was "10/20". These days with the prevalence of NLHE it should be written "10/20 Limit". This describes a game that the pre flop and flop you bet one unit, turn and river is two units, unless blinds are specified the default is small blind of half a unit (or so) and big blind a full unit.
A minus sign "-" denotes a spread limit. For example 2-6 means you can bet 2,3,4,5 or six. If the game had a couple of blinds I would write it like 2-6 1/2 blind for clarity, if written just 2-6 limit you could assume the blind was 1/2 or less like a single 2 blind.
Some games had rather complicated limits, at circus circus in Reno, the blind was one dollar, first two rounds you could bet 1-3, and the turn and river the limit was 3-6, This would be written 1-3/3-6.
La center WA had games structured were the blind was two dollars, and the bet or raise was two dollars and increased by one dollar each betting round, that would be written like 2/3/4/5
You could assume that the blind was generally the size of the first bet or there about. In limit blinds did not define the game the way they do in NL, the betting structure defines the size of the game, and blinds had a little variance.
For clarity these days you should precede the limit with the game you are talking about, 5/10 does not really mean 5/10 NL or 5/10 Limit.