Typically during a crisis, several hashtags appear, allowing the crisis to be followed with a high degree of precision, based on hashtags that identify given aspects of the crisis. Understand what the hashtag means. If you're trying to find out what a Twitter hashtag means, there is a site you can visit for some help: What the hashtag?
2. Never use a crisis hashtag for anything other than important information related to the crisis.
In many cases, those in the midst of a crisis are using the hashtags to relate real-time information to emergency responders and families and friends of victims. Emergency management professionals and a dedicated group of volunteers will also be using the hashtags to pass on critical information. Do not clutter important crisis hashtag streams with banter that does not advance a greater understanding of the crisis or in any way hampers the ability of victims, rescuers, relief organization, families and friends to convey critical information in the most streamlined manner. (You might consider including subject, without the hashtag.)
3. Keep advertising out of Twitter crisis hashtag streams.