Let's analyze each statement regarding *Berberis vulgaris*:
Statement I: Rapid change of symptoms - pain changes in regard to place and character is a feature of Berberis Vulgaris.
*Berberis vulgaris* is known in homeopathy for its characteristic shifting pains. These pains can change rapidly in location and in their nature (e.g., from sharp to dull, from one side to the other). This symptom of rapidly changing pains is a key indication for *Berberis vulgaris*. Therefore, Statement I is true.
Statement II: Berberis vulg. is indicated in complaints of drunkards after abstaining.
While *Berberis vulgaris* has an affinity for the liver and kidneys and can be used for complaints related to these organs, it is not specifically or primarily indicated for the withdrawal symptoms or general complaints of drunkards after abstaining from alcohol. Other remedies like *Nux vomica*, *Sulphur*, or *Quercus glandium* are more commonly associated with the after-effects of alcohol abuse. Therefore, Statement II is false.
In conclusion, Statement I is true, but Statement II is false.