- The symbol indicates a web page with an with calculation or data.

- The symbol indicates a web page with an with information for the given issue (it is the default page).

- The symbol indicates a web page with an list of symbol.

- The symbol indicates a web page with an image.

- The symbol indicates a web page with an unit converters.

- The symbol indicates a web page with an RAL colors.

- The symbol indicates a web page with an icon.

- The symbol indicates a web page with an basic equations.

- The symbol indicates a web page with an with information for users.

Basic - (example: Hydraulic engineering) searches for the entered expression in an exact match with the entry - i.e. in the order in which the words follow each other.

Logical OR - (example: butterfly valve OR lattice disc) pages containing one, the other, or both of the entered keywords will be included in the results.

Logical AND - (example: ASME AND internal pressure) only pages containing both required words will appear in the results.

Logical NOT - (example: spherical NOT ASME) pages containing the name "spherical" but not containing the word "ASME" will be displayed in the results.