In scientific papers there are asterisks representing the significance. Do these asterisks represent the significance level of the performed test or do they represent the obtained p-values? For example if you perform a t-test with a significance level of 0.05 and you get a p-value of 0.003. Then you have to reject the null-hypothesis. But can you put one asterisk (p<0.05) or two asterisks (p<0.01) above the graph if you make one?
There's not a single convention for asterisks. Sometimes they are for 10, 5 and 1% significance, or 5, 1 and 0.1% significance. Other times they could be in standard deviations and so on. You always have to read the table captions to see what they represent.
For instance, a table caption may say that the significance levels are given by stars: * - 10%, ** - 5% and *** - 1%. In this case a coefficient with ** would mean that the p-value was under 0.05. It's like Michelin rating - more stars, better. At least, that's what I see in papers.