The phrase "are often proprietary" is correct and usable in written English.
It can be used to describe items, information, or technologies that are owned by a specific company or individual and not available for public use.
Example: "Many software applications are often proprietary, limiting their accessibility to users outside the organization."
Alternatives: "are frequently owned" or "are typically exclusive".
Compared with for-profit products and services, which are often proprietary and protected with secrecy, nonprofits frequently share data, processes, and ideas in ways that spark multiplier effects for the greater good.
Approaches to zoning are often proprietary and vary widely.
Commercial formulations of SWEs are often proprietary, and the composition is largely dependent on the method of extraction.
Commercial formulations are often proprietary and the exact composition and extraction methods, shifting the burden to the research community to analyse and isolate the active components in these products.
In particular, Corder et al. has recommended using acceleration reported in standard units such as m/s2 or g's as opposed to activity counts or other conditioned data outputs based on arbitrary threshold criteria, which are often proprietary and manufacturer specific.
However, these tools are often proprietary (and therefore expensive) or complicated and lengthy to administer.
Even worse, FTL, which is considered as one of most important intellectual properties of flash-based storage, is often proprietary.
In fact, standards have always played an important role in high-tech, but they were often proprietary.
On the other hand, knowledge in the areas of formulation and fermentation is often proprietary in nature.
Most upskilling applications with similar features have limited usability for the garment industry; software is often proprietary, lacks integrative features, and is only available in English.
Standards are divergent and scarce, causing solutions to be often proprietary and non-interoperable.
