This document came out a few weeks ago but to answer the question lets use an example, let's use CHC.
You own 10 shares worth a dollar each, you have therefore $10 worth of equity in a company The rules of the NYSE require the shares to be worth over a certain amount (in this case a dollar). You are at risk of breaching the rules, or in CHC's case, breaking them for an extended period of time.
The shares are issued by the company so the company are allowed to change the make up of the share structure. Therefore they say ok we'll give you 1 share in the new structure for every 10 under the old one. Before, you had old shares worth a dollar each and you had 10 of them, you now have 1 share worth $10. Your value is preserved but the structure of it is different. It's all about the ratios.
Now, what the paper linked above says is that CHC will do the stock reverse split but the ratio is yet to be determined as they do not know what the value of the stock will be on the day it is effected.
It is pointless saying today, "Let's do 1:10" if the closing price when the stock needs to be changed is 10c as you are no better off than before (ie complying or risking compliance with the rules). The ratio CHC will use will be decided at the board meeting although I'm sure their bankers have some ideas about optimum trading ranges for the stock.
Note the volatility will likely remain with fewer shares on issue (poss even get worse as less liquidity) and the fundamentals driving the volatility have not changed so expect a wild ride, just with a more expensive stock.
Make sense?