"exception from the rule" is correct and usable in written English.
You can use it to refer to when something is not following an established rule. For example, "The restaurant made an exception from the rule and allowed us to bring our dog inside."
The specific issue in the AOL case concerned an accounting rule adopted in 1995 that carved out a small exception from the rule that advertising and promotional costs must be expensed -- that is, deducted from profits -- when they are incurred.
And, as Bill Moyers points out in the context of their intransigence on access to birth control, the bishops aren't content with an exception from the rule that, like other employers, they provide birth control coverage to workers in their hospitals and universities.
Co-occurrence data sets with exactly equal lists lengths are likely to be the exception from the rule.
This "limiting similarity" concept [7] may not hold under certain, narrowly defined circumstances [8], [9], but these instances are believed to be rather the exception from the rule [8].
Thus, the treatments that target GSA seem to be an exception from the rule that psychological treatments for IBS show large between-study variation in treatment effects.
The Nup98 FG domain is thus an exception from the rule that intrinsically disordered domains change rapidly during evolution (Denning and Rexach, 2007).
The German economic miracle as well as the ‚Trente Glorieuses' in France after World War Two are the exceptions from the rule over the last two centuries (Lutz 1984).
Taken together, there are more characterized "exceptions" from the rule that bacteria are monoploid than species that have been proven to follow the rule.
The only exception from this rule is the comparison between linear and non-linear transformation of the same parametric predictor.
