Revaluation is rarer than devaluation because the pressures are less acute: a country accumulating reserves faces no hard constraint in the way one losing them does. It is normally chosen to cool imported inflation, to reduce the cost of sterilising inflows as described in sterilised-intervention, or in response to trading-partner pressure.
The modern equivalent is often a managed appreciation rather than a single step: widening a band, adjusting a reference rate, or allowing a faster crawl in the strong direction.
For a trader the signature is a one-way market before the event, with the forward curve and the non-deliverable-forward market pricing a jump that spot is not allowed to make.
Example: a peg is moved from 8.00 to 7.60 per dollar, a 5% revaluation. An exporter's $10m of annual revenue falls from 80m to 76m in local terms, while imported input costs drop by the same proportion.
Related: devaluation, currency-peg, appreciation, sterilised-intervention