A more thorough explanation:

Definition: Scutagio habendo is a legal term that refers to a writ ordering a tenant-in-chief by knight's service to serve in a war, send a substitute, or pay a sum of money. It can also refer to a writ authorizing a lord who had served in the war or paid the required fine to recover the scutage from his knight's fees.

Example: If a baron fulfilled his contract or paid his fine, he would receive a royal writ de scutagio habendo. This writ would order the sheriff to cause him to have the scutage due from his tenants. However, before he could get his scutage, he would have to obtain something that the king is apt to treat as a favour.

Explanation: The example illustrates how scutagio habendo was used in medieval England to ensure that knights and lords fulfilled their obligations to serve in wars or pay fines. The writs were used to enforce these obligations and to ensure that the king received the scutage due from his tenants. The example also shows how obtaining scutage was not always straightforward and often required the king's favour.