As the temples were places of worship when they were built, there are a number of common rules and guidelines to obverse. Below is a list compiled by kompas.com. 

1. No vandalism 

Temples are invaluable legacies from ancient times. The centuries-old stones that the temples were built with are very vulnerable to chemicals and vandalizing the temples by leaving marks or scribbling on them is strictly prohibited. Such acts could lead to the destruction of the stones, and the loss of history.

2. Mind your selfies

While traveling these days cannot be separated from taking selfies, always bear in mind where you are. The majestic beauty of temples is undeniable, making them the perfect background in a photo. When posing for a photo near a temple, refrain from jumping in a group or climbing on a stupa. Such behavior could damage the temples to such an extent as to make restoring them next to impossible.    

Read also: Find serenity with the ancients at temples in Yogyakarta

3. Obey the rules

A number of temples have different sets of rules. What is allowed in one may not be in another. Pay attention to the rules and your surroundings, and always remember to respect the norms in the area.  

4. Respect worshipers

Some temples are still places of worship as well as tourist sites, such as Kalasan and Borobudur for Buddhists and Cetho and Prambanan for Hindus. Prayers and religious ceremonies may be in the process, so be considerate of worshipers by watching quietly from a respectful distance.

5. Be mindful

Some common rules include no littering, no running, no speaking in a loud voice and no swearing. 

6. Dress appropriately

Visitors should not wear footwear that could damage temple stones. Footwear with sharp fixtures and hard soles could cause irreparable damage to the stones. Cover your shoulders and legs. Some temples provide sarongs for visitors, but it’s always best to arrive prepared. 

https://www.thejakartapost.com/travel/2019/01/19/dos-and-donts-of-visiting-temples.html